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Picture of RFID Shielding Pouch Out of 'Trash'
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Choose when the digital info on your chipped passport and credit/ID cards is 'on' or 'off' by making a pouch or wallet that contains radio wave shielding/attenuating materials. This one is constructed from trash bags and cans of high-octane beverages consumed by real hackers.

Wrapping yourself in aluminum foil isn't enough! The kinds of radio waves used with RFID are tricky and can penetrate all sorts of things---it's a matter of power and antenna size. On a quest for a modern-day magic shielding cloth, I discovered how to make an effective, rigid pouch on the cheap.
  • Holds passport, 4-8 credit cards & moderate amount of folded paper.
  • Shields when closed, even when directly on top of readers.
  • Cards in can-lined pockets are shielded when pouch is open, also when on reader.
  • Inexpensive, readily available materials. Time is most expensive item on this project.
  • Pouch design works with the strap worn on the body or without & carried in another bag.
  • Shields more than some items currently available for sale.

Wikipedia on: RFID and radio waves

More technical details on page 21. Non-commercial use only, please. I made a batch for sale, but do not plan to be doing any more production. (There are about 3 left.) My personal motivation for this project was not pouch sales, but was in a sense my way of distributing "free condoms" for your personal info/privacy. Of course, I'm open to other opportunities. Contact me for more info.: saraheartburn (at) gmail (dot) com. 

Thanks, have fun, & be safe(r)!
 
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Step 1: Standards and materials for the whole project. BE SAFE.

Picture of Standards and materials for the whole project.  BE SAFE.
A. All quantities are listed with a # -- #4 = four pieces

B. All measurements are in INCHES followed by CENTIMETERS IN PARENTHESIS.
Example: #4, 3 3/4 x 1 7/8 (9.6 x 4.8)

C. Any time you're instructed to 'fuse' or 'iron' it is implied that you are doing so BETWEEN two sheets of parchment paper, AND THAT YOU'RE WORKING IN A WELL-VENTILATED AREA! Bre Pettis of Make made an awesome podcast on how to make a messenger bag out of trash bags. It shows in detail how to fuse plastic trash bags together. Watch it! Make a Messenger Bag out of Trash Bags

D. Use a zipper foot for all sewing

E. The photos shown are a collection from making several different pouches. Some of which are before I added the angled pockets to the design.

Gather materials
  • Black trash bags--(Husky brand) heavy duty 'construction cleanup'
  • Clear trash can liners of the same size --(Husky brand)
  • Aluminum cans
  • Aluminum sheet metal .032 (.08) thick
  • Box cutter utility knife w/strong blade
  • Xacto knife and No. 11 blades, or blades of that shape
  • Straight edge
  • Cutting surface (self-healing mat or thick cardboard)
  • Strong utility shears or tin snips
  • Scissors
  • Medium grain sand paper
  • Medium file
  • Iron & ironing board
  • Parchment paper, the kind used for baking
  • Sewing machine with medium to heavy duty needle, zipper foot. Intermediate sewing skills are very helpful.
  • 3/4" (2) wide Velcro. Self-adhesive is great for positioning.
  • 1/2" (1.3) or 1" (2.5) wide masking or other paper tape
  • Black electrical tape

Optional:
  • 60" (153cm) of 1/8" (.32) thick screening spline (looks cool with the fused black plastic) or any kind of cord for a strap
  • band saw
  • mini iron--used for applique ironing
  • block for sand paper
  • The clear trash can liners could be optional. You wouldn't be able to see the cans you used--which is a fun design element and also makes it much easier when you're stitching the pockets. Flip the can over so that no printing is showing if you are offended by logos, etc.

Lady Safety says, "SAFETY FIRST!" :-D
***EXTREMELY IMPORTANT:*** Ironing or melting any kind of plastic produces toxic fumes that are colorless and often odorless. Do this in a well ventilated area. Well ventilated means a garage with the door open; out on your patio; a large room with a window and door open & fan blowing out the window for generous cross ventilation. Seriously, these fumes can possibly make you very sick or dead. If at any time while you are fusing plastic you feel woozy or headachey stop immediately, and get outside for fresh air. Then increase the ventilation in the area you are working in.

Wear eye protection when you're cutting and filing metal. You should probably wear eye protection when you're sewing around the aluminum. At one point I hit the sheet metal by accident and the needle shattered and hit me in the face.

Always use a sharp blade when cutting. As soon as you have the thought "this is starting to get dull..." replace the blade. The cost of extra blades is much less than a trip to the ER for stitches, and ensures clean edges on your projects. Always be mindful of the position of your hands vs. the potential path of a blade: thumb on ruler, etc. especially when sawing into aluminum cans with a utility knife.

Step 2: Cut, file, sand aluminum sheet metal pieces: #2, 4 1/2 x 5 1/2 (11.5x14)

Picture of Cut, file, sand aluminum sheet metal pieces: #2, 4 1/2 x 5 1/2 (11.5x14)
a. Measure then cut on a band saw. If you do not have access to a band saw, the retailer you purchased the sheet metal from can probably cut the pieces for you for free or a small fee. Some say tin snips will work.

b. File off any rough parts. Burs and sharp edges will quickly wear through the plastic. Files work best with a forward action.

c. File corners until round, 1/4" (.65) corner radius.

d.. Sand all remaining rough and jagged bits until smooth.

Step 3: Cut aluminum can pocket panels: #4, 3 3/4 x 1 7/8 (9.6 x 4.8)

Picture of Cut aluminum can pocket panels: #4, 3 3/4 x 1 7/8 (9.6 x 4.8)
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a. Rinse out the aluminum can and lay it on its side. Using the utility knife, cut the top and bottom off the can. Cut just inside the bends and curves of the ends of the cans so you end up with a flat piece. Pierce with the point of the knife first and then saw down. The blade often sticks then slips and cuts, so go slow and try to avoid putting too many dents in the can.

b. Using the shears, cut the aluminum can tube lengthwise so you have a rectangle. Bend and work the pieces gently in the opposite direction of the curve. Make them as flat as possible without putting too many dents in them.

c. Cut paper pattern pieces: #4, 3 3/4 x 1 7/8 (9.6x4.8)
*Shortcut* fold your paper into four layers. Measure on top and cut out all four pieces at once using your straight edge and xacto.

d. Consider how you want the printing of the cans to be viewed when you tape the pattern pieces on with masking tape. The front, bottom pocket will show the most, while the other pockets will show just a little of their top. Cut each rectangle out with the shears.

e. Cutting off as little as possible, round the corners with the shears. Corner radius is approx. 1/4" (.65).

Step 4: Cut plastic bags

Picture of Cut plastic bags
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#9, 8x16 (20.5x41) black rectangle strips
#21, 8x8 (20.5x20.5) black squares + several extra pieces for testing how to fuse
#21, 8x8 (20.5x20.5) clear squares + several extra pieces for testing how to fuse

(These are 'soft' measurements. If you're off +/- a half inch or so, it's OK)

a. Cut plastic bags using a straight edge & Xacto. The different bags I used were almost the same size, so that made things easy.

b. Unwrap one bag from the roll. Do not unfold the bag. It's easier to cut strips off while the plastic bag is still in a long, folded strip. Draw the bag across your cutting surface and cut off strips approx. 8" (20.5) wide.

c. Unfold those strips so they are at #4 layers thick. Slice off the folded ends so you end up with a neat stack of plastic bag strips. Cut in half for your squares.

**Important Note** these bag cutting instructions and quantities of layers relate to the size and kind of bags I used. Improvise for what you have available to you. The goal is to have layers of bags as uniform in dimension as possible.

Step 5: Fuse layers of bag together to make the main body and plain pocket pieces

Picture of Fuse layers of bag together to make the main body and plain pocket pieces
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make #2: #4 layers of 8x16 (20.5x41) black plastic rectangles together to make one fused sheet. These will become the main body of the pouch. Set aside.

make #2: #3 layers of clear squares on top of #3 layers of black squares to make one 8x8 (20.5x20.5) sheet. These become the passport and angled pockets. Set aside.

Remember to fuse between sheets of parchment with a lot of ventilation around you. Do not contact the plastic directly with your iron. If you do it will melt immediately, so wipe it off the iron with a dry rag while the iron is still hot. The temp that worked on the iron I used was just between 'wool' and 'cotton.' Keep your iron moving at a slow and steady pace using moderate to firm pressure. Adjust the iron temp as needed. Some plastics fuse and shrink more than others. When you combine plastics that shrink differently, you get curling.

a. Test fusing only the black pieces together, then fusing the black plus clear together. It should not bubble, but it may make an interesting puckering pattern. In the messenger bag video they recommend using wax paper, but I prefer parchment. The same two pieces can get you through the whole project. When you are melting and fusing properly, the plastic looks like it becomes a little greasy and sticks slightly to the paper.

Test fusing: Place #4 layers of black plastic bag between two pieces of parchment paper. Run the iron over for a little bit. Flip the whole parchment paper & plastic sandwich and iron the other side. Get a good feeling for how much you need to iron to get it fused together. I used a piece of thick aluminum sheet metal to rub the surface of the sandwich to suck up the heat and help keep the pieces from curling. Check the plastic to make sure it's one piece and not still in layers. Re-iron if needed. Next try fusing three layers of clear to three layers of black. Save the test pieces you've made for testing how the material goes through the sewing machine and making appropriate adjustments for tension.

b. When you think you have mastered fusing, proceed to fusing the work pieces listed above.

Note: The quantities listed for how many layers you fuse together relate to the thickness of the trash bags I used. If you use thinner bags you'll have to fuse more layers together. The clear liners I used were thinner than the black bags. You want to end up with thick, but still flexible material. The pocket pieces should be slightly thinner and more flexible than the main body pieces.

Step 6: Fuse aluminum can pieces into squares of plastic

Picture of Fuse aluminum can pieces into squares of plastic
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Lining the pockets with aluminum can pieces allows your cards to remain shielded while the pouch is open. Each can piece is fused between #3 layers of clear and #3 layers black squares.

a. Lay down #3 layers of clear 8x8 (20.5x20.5) squares. Whichever side of the can you wish to have visible, place face down upon #3 layers of clear plastic. Center can piece in the square, a good 1" (2.5cm) from the top. Fuse. Repeat for the other three pieces.

When I ironed my can pieces, I found that the clear plastic shrinks more than the black and if I ironed the face of the cans too much it puckered and curled. Rubbing the 'heat sink' on top of the parchment to cool and flatten was very helpful. (Don't have a thick piece of sheet metal? Use the bottom of a frying pan.) Spend more time with the iron on the perimeter of the can pieces and keep the iron on top of the can pieces only long enough to fuse it. If you mess up, cut the can piece out of the plastic and do over. The plastic does not adhere to the aluminum.

*Optional: use only black bags and have the cans invisible. I liked the cans showing and it is MUCH easier to see them when you're sewing the pockets.

Step 7: Trim & finish the edges of pocket pieces

Picture of Trim & finish the edges of pocket pieces
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a. Using your straight edge and xacto knife, trim the top, short edge of the can pocket pieces to 3/8 in. (1). Place your straight edge parallel to the short end of the can piece (so you can still see the entire piece of can) and then cut a straight line the entire width of the piece, 3/8 in. (1) from the top edge of the can.

b. Fold the trimmed edge over to the front and firmly burnish the crease with the edge of your thumbnail: press and rub the fold firmly as if you were creasing a piece of folded paper. Make it straight across the entire width of the piece.

c. Place the piece face up and while holding the scored "hem" in place, place the other piece of parchment on top. You have to be a bit dexterous with holding the parchment and fold-over in place and avoiding ironing your fingers. Try tacking a few places with the tip of the iron and then ironing the whole side. Do your best to iron only the edge and with firm pressure and slow movements, fuse the 'hem' to the face of the clear plastic over the can piece. Do not flip over and iron the other side. Be sure it's melted to the face and not just creased over. Go slow and carefully. Check and re-iron if you need.

Shown is my small iron with a small piece of parchment under it. This was easier to show what exactly is being done, and wrangle a small area, but it's not necessary to have a small iron like this to complete this project.

Step 8: Trim and finish the edge of the passport pocket

a. Take #1 fused 8x8 square with no can in it that you made in step 5 and trim a small amount off the one edge that will be the top of the pocket.

b. With the clear layer of plastic facing up, fold the trimmed edge and over 3/8 in. (1) to the front, crease, and fuse to finish the edge in a straight line the entire width of the piece--just like the previous step. This becomes the passport-sized pocket that goes behind the can-lined pockets.

(will get a photo soon!)

Step 9: Test stitching plastic, sew the two main body pieces together

Picture of Test stitching plastic, sew the two main body pieces together
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a. Get some of those 4-layer pieces you set aside from mastering the plastic fusing process. Put one on top of the other and stitch some test seams through the sewing machine. Adjust the tension and foot pressure as necessary. Use larger stitches. Some machines will feed it with ease, others will need some help guiding it through.

b. Lay the two 8x16 body/rectangle pieces on top of each other, aligned, and fold both pieces in half. Firmly burnish the crease with your thumbnail. Unfold, keeping the pieces aligned and nested within their creases.

c. Using the fold as a guide, apply a length of 1/2" (1.3) wide masking or painters tape as straight as possible on either side of the fold. Wrap the ends of the tape to the other side towards the center fold so that the two plastic sheets are secured and aligned together. These will be your guides for the first two stitches. *The image is showing yellow electrical tape. Electrical tape is too sticky to the bottom of the sewing foot and makes it very difficult to feed through the machine. Use paper tape!

Important note: If you do decide to use a cord to make a strap, you may wish to increase these measurements of the middle fold area slightly wider (about 1-2x the width of your cord) to accommodate the cord and allow for the bulkiness of putting more items in the pouch.

d. Stitch a straight line on either side of the tape, as close as possible to it, so that you end up with two parallel stitches, each just past 1/2" (1.3) from the center crease. Remove the tape.

Step 10: Sew the sheet metal pieces into the body

Picture of Sew the sheet metal pieces into the body
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a. Open up the top layer of one side, place the 4 1/2 inch edge of one piece of sheet metal between the two layers, flush and square against one seam, centered in the width of the piece. Tape into place with pieces of black electrical tape.

b. Close the flap and on the outside, find and burnish the edge of the metal so you can get a visual guide where to stitch.

c. Using the zipper foot, stitch a 'U' around and as close to the sheet metal as possible. Using the zipper foot properly will ensure you have a close seam and that you don't feed the metal up and under the needle. Whenever you need to stop sewing and rotate the piece in the machine, lift the presser foot and do so when the needle is down in the material. Back-tack a couple times at the beginning and end of those seams.

d. Repeat for the other side. When taping in the second piece of sheet metal, test that when folded squarely in half, both plates align on top of each other. This is very important.

Step 11: Sew the passport and card pockets together

Picture of Sew the passport and card pockets together
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The pockets are first stitched together and then attached to the main body.

a. Place the plain, square and hemmed passport pocket piece on your work surface, hem towards the top and facing you. Lay on top of that one of the pieces of aluminum can fused pieces. (This will be the highest pocket. Only a small strip of the can printing will be showing when finished.) Align the top of the hemmed edge of the can pocket piece 1/2 in. (1.3) below and parallel to the top edge of the passport pocket piece behind it. Use masking tape on the sides to hold in place. Stitch straight along the bottom of the can, right next to it. Stitch only the width of the can piece. Be sure to back-tack a little bit on either end of the stitch.

b. Trim the excess of the top layer 1/4 in. (.65) below the seam, straight along the entire width of the square. Remove the masking tape.

c. Take another can piece and align it just below the pocket layer you just stitched on, the same distance and parallel from the top edge of the layer below it. You can now use the edges of the cans for horizontal alignment. Tape in place. Stitch just below the bottom edge of the can, the width of the can, through all layers of the plastic. Trim the excess below the seam. Repeat one more time for the third pocket.

d. For the final, front pocket, align and tape it as you did the others. Starting where the highest can pocket meets the passport pocket behind it, sew a 'U' down the sides of all the can pieces, along the bottom and back up the other side. Sew just next to the aluminum. Back-tack an extra couple times at the beginning and end where the top pocket is attaching to the passport pocket to reinforce. While you are sewing, back-tack over the edge of each pocket piece. DO NOT TRIM OFF the excess of this front, top pocket.

Step 12: Sew passport and card pockets to main body

Picture of Sew passport and card pockets to main body
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a. Lay the pouch open, inside facing up on your work surface.

b. Place the sheet of pockets on top of the right side, aligning the bottom seam of the bottom pocket so it's just above the bottom seam of the main body where the sheet metal is stitched in. Center horizontally and tape into place.

c. Sew a 'U' closely around the outside perimeter of the sheet metal. Start the seam where the top of the passport pocket meets the main body and go around from there. Be sure to back-tack a few times to reinforce the top edges of the pocket. Go slow. It could be helpful before you sew to burnish the edge with your thumbnail to provide a visual guide. Going slow will allow the zipper foot to do its job and keep the needle from running into the sheet metal. Do not trim any excess.

Step 13: Cut, finish edges of angled pockets

Picture of Cut, finish edges of angled pockets
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The other plain, fused square is used to make both angled pockets. I measured these angles mostly by eye. Study the photos, they will help. A less complicated option would be to make two horizontally aligned pockets, but the angles are neato.

a. Lay the pouch open with the pockets facing up. Lay the fused square pocket sheet on top of the panel where it's going to be attached. Fold back at the angle you would like for the large pocket. Approximately 45° is about right. Crease firmly. This will be your cutting guide.

b. Remove the creased square and cut along the crease with your straight edge and xacto to make #2 angled pieces.

c. For contrast, I made the large pocket with the clear plastic facing up and the smaller one with the black facing up. Turn the edges over to the front and fuse the 'hems' like you did for the other pocket pieces.

Step 14: Attach angled pockets

Picture of Attach angled pockets
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a. Align the pockets on top of the pouch as they will be sewn and tape them to each other. The angled end pieces should be a good .5 (1.27) away from the top edge and inner seam. Remove the two pockets that are now taped together and apply a basting stitch along the outside long edges to secure them together.

b. Tape the basted pockets back onto the pouch as shown. Like you did in step 10, run your thumbnail along the edge of the sheet metal underneath to make a crease and sewing guide. Stitch a 'U' around them the same way you did the other set of pockets. Back tack a few times over the edges of the pocket 'hems.'

Step 15: Attach Velcro, double stitch

Picture of Attach Velcro, double stitch
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a. Measure and cut a length of Velcro the width of the pouch---the distance between the outer seams around the velcro. With the two velcro pieces stuck together, round the corners.

b. Place the Velcro pieces just below the bottom seams. Test alignment by closing and inspecting before stitching. Stitch just inside the edge of the Velcro, around the whole perimeter of it, and back-tack extra on the short ends. Because of the size of my sewing machine and how rigid the pouch is, I was unable to fully rotate the pouch under the needle. Sew down one length of the velcro, back-tack across the width a couple times, and then stitch backwards back up the other side of the velcro.

c. Double stitch around the entire circumference of the body of the pouch, 1/8" (.32) from the inner seams, sewing down and around the bottom of the Velcro.

Step 16: Trim out whole pouch body and round corners

Picture of Trim out whole pouch body and round corners
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After spending hours of constructing, this is perhaps the most nerve-wracking step. Using a metal straight edge with a cork bottom and a brand new #11 xacto blade will help.

a. Close the pouch together so that the Velcro, plates and outer seams are aligned. Check alignment again! Lay the closed pouch on your cutting surface and along one long edge, and align your straight edge 1/8 (.32) away from the outer seam. Give yourself a little bit more room if your stitching is not very straight or consistent to avoid cutting into the outer double seam.

b. Apply very firm pressure to the straight edge and with a slow firm cut, slice off the excess, cutting through all the layers at once. (You may have to do this in a couple cuts.) Repeat for the other side. Do the same for the short, bottom edge by the Velcro.

c. Cutting through both sides at once, round the corners. You can get away with cutting one corner at a time if you wish.

Step 17: Fuse one layer of plastic to outside and trim

Picture of Fuse one layer of plastic to outside and trim
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One layer of plastic on the outside will cover your threads and seams, and provides a great finished look and a smooth surface for an applique design.

a. Lay the open pouch pocket side down on the ironing board and place #1 8x16 (20.5x41) strip of black plastic on top, allowing a good inch extra on all sides. Fuse with the iron. It takes much less time to fuse one sheet to the outside. You can always re-apply the iron if it didn't melt enough. You may wish to work some of the areas with the small iron if it didn't fuse uniformly.

b. Turn over and trim as shown. Width of trim = width of the innermost seam to the edge of the pouch + the thickness of the pouch. Trim the corners as shown.

Step 18: Fold over the edges and fuse to the inner seams to finish

Picture of Fold over the edges and fuse to the inner seams to finish
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a. Fold over and fuse the corners to the inside first.

b. Fold over and 'tack' some points of the long edges, then fuse the rest. The goal is to cover the rough edges and seams for a clean finished look. With the small iron it is easy to iron all the little sides and bits. You can easily hold a small piece of parchment over whatever plane or edge you wish to fuse.

Step 19: Optional: Stitch in cord

Picture of Optional: Stitch in cord
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a. Measure a loop of cord to however long you wish. To wear mine across my body, I used 60" (153) of 3/16" (.4) screening spline. Overlap the ends 1" (2.5) to form a loop and hand sew together securely. To pull the needle through the screening spline, I needed to use some rubber hand sewing traction gripper disc thingy. Or cut the ends at a sharp angle, super glue them together and wrap in a thin, flat spiral of electrical tape.

b. Using black electrical tape, tape the loop into the inside crease of the pouch. Have the part where you stitched it together in there.

c. Close and top stitch the cord into place. Back tack a few times on the edges. You will need to help push the pouch through the machine. Test top stitching a cord into a thick mass of folded fused plastic scrap if this is a first for you.

Step 20: Optional: Personalize with a fused 'logo'

Picture of Optional: Personalize with a fused 'logo'
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Put your mark on the front by fusing a stencil-cut design made from a sheet of fused plastic. Many options for contrast, transparency or embossed looks. The mini iron lets you be precise. Test on scrap first!

Jolly Roger Design:
a. Fuse #3 layers of clear plastic together.

b. Tape paper outline on workspace. Tape fused clear sheet on top. Trace outside perimeter with black fine point sharpie. Cut out with xacto.

c. Fuse to the outside. The clear plastic can disappear into the black quickly creating a funky, printed varnish look.

Step 21: More technical bits

Picture of more technical bits
Update, 23 Oct 07: Will this go through airport security without problem? Yes! Traveling to and from ToorCon, I had no problems with security. On the way down, I had 7 pouches, put them all in a plastic bag, and placed them in the bin next to my bag of travel-size liquids. No problems in Seattle, Phoenix and San Francisco!

  • Tested at 125kHz and13.56MHz on commercially produced readers and tags in the wild (Seattle metropolitan area) and in a fantastic collaborative hackerspace lab lair. We have yet to acquire use of a spectrum analyzer and related antennas to rigorously test and quantify the specific amount of shielding/attenuation... requests are out to the tooth fairy.
  • Some instances tags were shielded while in the plain pockets, with the pouch open. Direction of pouch in relation to antenna affects amount of attenuation. The electromagnetic properties of the environment affect attenuation. Electromagnetism is cool and fun to learn about. Some people call antenna design a 'magic black art!' Go investigate! Did you build and then 'break' this? Let me know.
  • Tested a compact sleeve available for sale. It allowed a card to be read when placed on a reader. A faraday wallet shielded when closed, but tags could be read when it was open.
  • Explored shielding properties of various combinations of these materials: catalog-ordered conductive textiles, layers of aluminum foil, aluminum screen, aluminum tape, zinc plate, kittens, and special lab helpers.

A coincidental fact relating to the date this instructable was published: On October 17, 1907, a defining event in world communication occurred on a bog outside of Clifden, Connemara, Co. Galway, Ireland. The first commercial transatlantic message was transmitted from Guglielmo Marconi's Station in Clifden to his North American complex in Glace Bay, Nova Scotia, Canada. This message effectively launched the concept of telecommunication accessibility for all. Wikipedie on Marconi

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  • RFID
  • passport
  • security
  • shielding
  • trash
  • wearable computing
  • wearable technology

Hrmm...what happens if one closely surrounds the RFID chip with some shielding, THEN with more RFID chips? I'll need to try this. Hope others will, too. Getting the data from a single chip inside a pile of chips should create a challenge for a chip reader. I can't be the first one to have thought of this. Another idea: tap the antennae of the surrounding RFID's and add some more antenna surface to each, so they present stronger signals than the one you're concealing? If I were building a reader, I'd have it looking for the strongest signal. This would (maybe) leave the signal of the chip that's being protected look like background noise?

Laral1 month ago

Wow! This is one of the best I'bles I've ever seen. It is well-documented, well-researched, well-thought-out, well-implemented, and well-tested. Brilliant! A model of how all I'bles SHOULD be, but aren't. Kudos to you!

You deserve at least a free one-year PRO membership if you haven't received one already.

laras (author)  Laral1 month ago
Thank you! & no, I haven't received any free stuff from Instructables for my efforts.
Laral laras1 month ago

Well you should. I'd recommend you but I'm just a peon around here. I did get a couple years' worth of PRO membership free for my stuff. I think it is based on how many views and favorites and if a staff person happens to see and like your stuff.

laras (author)  Laral1 month ago
I'm almost too busy making things to also be making instructables.
Laral laras1 month ago

I know the feeling. I probably publish about 1% of my personal projects here. It takes a lot of time to photograph and document a procedure and list materials and so forth. And I won't half-ass it like some people do. I believe in quality, not quantity, like you.

chasmyn4 years ago
Okay, WAAAAY back when you posted this or something I said I was going to make this pouch out of fabric, and you said, "great, I'd like to see it!"

Well...I think it's been 2 years maybe? I FINALLY actually did it, even though the metal pieces have been cut this whole two years. So here is my interpretation:

P1010342.JPGP1010343-1.JPGP1010344-1.JPGP1010345-1.JPGP1010347.JPGP1010348.JPG
chasmyn chasmyn4 years ago
Also? I didn't add a strap, but made the spine wide enough that should I choose to add the strap later, I can. I'm also thinking of adding some velcro or something as a clasp. I wish I were tutorially gifted so I could render my interpretation into a tute for folks who want to sew these, but honestly, I'm not entirely sure how I made this happen. sometimes I get the sewing machine out and magic happens. Mostly because I have other people's directions that I can somehow make into my own interpretation.

Also? I love the goggles in your profile pic. Shiny!
laras (author)  chasmyn4 years ago
I love the batik. It looks so much nicer than melted plastic. And less stinky too!
yay, someone made my pouch!

I'd love to hear how it works after you're out and about.
Thanks for posting. what a treat :-)
laras (author)  chasmyn4 years ago
This has made my day!
Great Instructable. I learned something I should've known already, I love that!
Vectorr4 years ago
Can I make a wall poster of "Enthusiastic lab helper?"
She's cute. ;X
static4 years ago
Nice instructable and a good looking finish on the final product. But after much scrolling back and forth and opening all the photos, I'm seeing too many "holes" that have doubt the effectiveness of it, particularly with systems that use higher frequencies.. No full metal boxes around the card pockets no shielding at where the pouch folds over. I would at least fold the aluminum around a credit card and crimped the edges or use metal screening between the outer and inner pooch materials.
cmrc6 years ago
Could you use old potato chip bag material? I was at a CERT conference once where an FBI agent said that they store suspect phones and electronic RF devices in potato chip bags because the signals cannot escape the bag. Just wondering if that was true or not.
static cmrc4 years ago
Some chips bags are Mylar that are aluminized on the inside. So they should work as RF shielding.
laras (author)  cmrc6 years ago
good question!

potato chip bags are made of mylar — one of the materials tested during the prototype stage. mylar was found to attenuate cell phone signals, but the frequencies for RFID are lower and the tests i did showed the mylar had little effect. the lowest possible cell phone signal tested was 900MHz (using the phones of friends, etc--american phones.) the goal was to block the most common frequency used for RFID tags = 13.56MHz. the mylar had unmeasurable/unnoticable effect on those tags and the even lower frequency tags of 125-130KHz like the kind used for pet ID chips. the lower frequencies are tricky. they can penetrate metal, water and even kittens---then again they operate in the "near field" = 1 meter or less.

to answer whether that FBI agent was speaking the truth is tricky. it is very possible that sticking a cel phone in a potato chip bag will attenuate the receiving and emitting signals enough so that it doesn't work. as for "other RF devices", it will depend totally on what frequency the device is operating on.
cmrc laras6 years ago
Thanks for the information. I had wondered if the frequency would make a difference in results.
Though it's a bit less likely than someone gathering RFID information, I think it's worth noting that this bag should also protect complex electronics(anything with a circuit board. Cell phones, laptops, etc.) from an EMP. (Electromagnetic Pulse)
It'll also stop most cellphones from getting reception, thus going into 'seek' mode and ending up with a dead battery.
cory.smith4 years ago
Sweet. I won't be making one, as I really don't have the need, but I'm glad I read it. =D And your knowledge of radio signals is pretty impressive...5 Stars
RaNDoMLeiGH5 years ago
You might want to put a copy of the Bill of Rights in your bag, just in case. They have one printed on sheet metal for $4. It's guaranteed to set off the metal detectors at the airport.

I got mine at the Penn & Teller store at the Rio in Las Vegas, but there are other sources around.

here's a cute article (scroll down a bit):
http://securityedition.com/category/good-news/


eclipsed6 years ago
What about an altoids tin? Would that work for shielding credit cards? Also what about using thin pieces of lead foil instead of sheet aluminum? Does that block the scanner? I have a bunch saved from the tops of wine bottles, from years ago when they used lead for that. They are more flexible than aluminum and won't even break the needle, I think it would go right through them since a steel needle is much harder than (thin) lead.
laras (author)  eclipsed6 years ago
I haven't tried an altoids tin yet. I say try it if you have any kind of ID badge or chipped card. Lead should work great too -- pretty heavy though.
bytowneboy7 years ago
Exceptional!!
jafo7 years ago
To add some additional information to this thread, the following was taken verbatim from Wikipedia. Bracketed numbers are supporting data reference numbers.
~
Shielding

A number of products are available on the market in the US that will allow a concerned carrier of RFID-enabled cards or passports to shield their data. In fact the United States government requires their new employee ID cards to be delivered with an approved shielding sleeve or holder[citation needed]. There are contradicting opinions as to whether aluminum can prevent reading of RFID chips. Some people claim that aluminum shielding, essentially creating a Faraday cage, does work.[59] Others claim that simply wrapping an RFID card in aluminum foil, only makes transmission more difficult, yet is not completely effective at preventing it.[60]

Shielding is again a function of the frequency being used. Low-frequency tags, like those used in implantable devices for humans and pets, are relatively resistant to shielding, though thick metal foil will prevent most reads. High frequency tags (13.56 MHz — smart cards and access badges) are more sensitive to shielding and are difficult to read when within a few centimetres of a metal surface. UHF tags (pallets and cartons) are very difficult to read when placed within a few millimetres of a metal surface, although their read range is actually increased when they are spaced 2–4 cm from a metal due to positive reinforcement of the reflected wave and the incident wave at the tag. UHF tags can be successfully shielded from most reads by being placed within an anti-static plastic bag.
~
Researchers at two security conferences have demonstrated that passive UHF RFID tags, not of the HF type used in US passports, normally read at ranges of up to 30 feet, can be read at ranges of 50 to 69 feet using suitable equipment.[64][6
~
The potential for privacy violations with RFID was demonstrated by its use in a pilot program by the Gillette Company, which conducted a "smart shelf" test at a Tesco in Cambridge, England. They automatically photographed shoppers taking RFID-tagged safety razors off the shelf, to see if the technology could be used to deter shoplifting. This trial resulted in consumer boycott against Gillette and Tesco. In another incident, uncovered by the Chicago Sun-Times, shelves in a Wal-Mart in Broken Arrow, Oklahoma, were equipped with readers to track the Max Factor Lipfinity lipstick containers stacked on them. Webcam images of the shelves were viewed 750 miles (1200 km) away by Procter & Gamble researchers in Cincinnati, Ohio, who could tell when lipsticks were removed from the shelves and observe the shoppers in action.[citation needed]
~

Since the above information are only segments it might be said by some that they are out of context, so if you wish to read the other surrounding information, please go to:
http://en.wikipedia.org/wiki/Rfid
and read it all, including a huge number of references containing additional data.

BTW, great work on the research, construction, and testing!
line1917 years ago
Thanks so much for your Instructable. I am getting one of the new passports soon, and I have so say that I am not thrilled about it. You said that you explored some of the conductive textiles as well as some of the passport sleeves online. Do you have more details about that? Was the tin can approach not enough for the passport? or did you just want something sturdier? I have a BS in physics, so I know about the science, but I don't have access to any of the equipment necessary to do the testing, I would be really interested in more of the details of your tests. I was thinking about ordering some of the fabric from http://www.lessemf.com/fabric.html, and just making a crafty little pouch, but I would prefer on that actually works... Do you know the frequency of the passport signal?
beep1o7 years ago
Anyone know if airport security will freak out if this is your bags?
laras (author)  beep1o7 years ago
See pg. 21 for an updates on traveling and dealing with security.
Shadyman beep1o7 years ago
You should have no problems with Security.. As long as you put it in the little trays that go through the X-Ray. They'll probably freak out and want to look through it, though, when it turns up as metal to their machine. Oh well.
laras (author)  beep1o7 years ago
i'll be experimenting with that this weekend. i have a few friends who have traveled with one already and haven't heard anything negative yet.
Keso7 years ago
I'm really impressed with the attention to detail put into this instructable. I think you've raised the bar with this. Well done!
chasmyn7 years ago
I'm wondering how important the plastic is to security? I mean, can I use fabric instead and still be protected? I'm not keen on melting plastic, but I want the bag to be secure. Thanks!
laras (author)  chasmyn7 years ago
The fused plastic is a way to get a funky, durable material, and an opportunity for recycling (or some people call 'upcycle') The amount and arrangement of aluminum is what makes it shielded. You could use fabric. I want to see a pic! :-D
dentsinger7 years ago
Hehe, I can't help but notice the table in step 21 photo. Nice.