If you want to hide something in a place that no one will look, stick it in a tampon. Guys will steer clear of it and girls won't think anything of it. I use this to hide emergency cash on trips, but you could also stash expensive jewelry or other small items.
Step 1: Materials
Tyvek paper (I used a section of a FedEx envelope)
white glue (I used quick dry tacky)
full sized paper wrapped tampon with cardboard applicator
scotch or masking tape
color copier or scanner/printer
Step 2: Prep Tampon Wrapper
Cut the ends off the wrapper just below the seams.
Set the tampon aside.
Trim down the side of the wrapper's seam.
Your wrapper should now be flat.
Step 3: Tyvek Wrapper
Copy the wrapper with 110% magnification. Basically, you need to enlarge the image, adding a few extra centimeters, to make up for the ends you cut off earlier.
Once you've got the copied image the appropriate size (the same length as an unwrapped tampon), tape a piece of Tyvek over the image on the copy paper.
Print the image again over the Tyvek. I used an ink jet printer, but a laser printer should work as well.
Take the Tyvek off the copy paper and trim off the excess. Don't forget to leave the white seam if your brand has it.
The Tyvek doesn't have the same texture as the original paper, so the original wrapper needs to be glued to the Tyvek. It won't cover the whole thing, but when assembled, the difference at the edge will be camoflaged.
Apply an even layer of glue over the entire back of the original wrapper and apply it to the Tyvek so it lines up with one corner. Do not put it in the center.
Step 4: Closed End
Apply glue to the inside of the end where the Tyvek and original wrapper are flush.
Put some sort of clamp or heavy object on the end.
Use some sort of long object like a knitting needle to puff up the inside of the wrapper so that only the end that's clamped gets glued.
Allow to dry.
Step 5: Open End
Cut a few small pieces of aluminum tape and apply them to the inside of the open end of the wrapper about a centimeter from the edge. I applied two layers of tape.
Now you can fold up the end to hold your items in and it looks like it's sealed.
Step 6: Applicator
Pull the tampon out of the applicator. Discard the tampon.
To prevent the two pieces from being pushed together when inserting objects, apply glue to the edges where the two sections overlap.
Allow to dry.
Insert the cardboard applicator into the wrapper.
Step 7: Enjoy
Hide your valuables with confidence. It's so innocuous, no one will look twice at your secret stash.