*As featured on http://reuseandupcycle.blogspot.com *

Do you have piles of plastic grocery bags lying around? Do you feel guilty throwing them away, but don't know what to do with them? Well over the course of this instructable, I will show you how to turn your bundles of bags into a comfortable, sturdy*, up cycled hammock-style swinging chair. All you need is a little bit of spare time and grocery bags and soon you'll have your very own Up-swing!

*this chair has been tested up to 220 lbs.

Step 1: What You'll Need....

1. LOTS of plastic grocery bags, about 500. You can either do the first steps of this project as you get grocery bags, or else you can ask friends and family or even collect them from grocery stores.

2. 2 carabiners. I used 7/16" Spring Link carabiners from Homedepot.

3. 6 feet of thin rope. I used 3/16in x 100ft of Braided Nylon & Polypropylene Rope from Homedepot.

4. Someplace to hang it. I attached it to a piece of ply wood held between two beams on my ceiling, but you can hang hooks in a ceiling or hang it from a tree outside.

Step 2: Braid Bags

You will need to make 26 7 yard-long ropes and 20 4 yard-long ropes.

SInce the 7-yard long pieces are the bulk of what you will need, let's start with them first.

First take two plastic grocery bags and cut them into thirds (check the photos above).
Unfold the center piece. This is your first strand.
Take the two side pieces and cut the handles apart and down the sides until you reach the bottom of the bag to make two long strands.
Repeat this process with another plastic bag.
Take four of the six strands and tie them together into a knot. Don't pull the knot very tight yet because you may want to increase the length of the chair later on, in which case you will need to take the knot out. One of the strands will be shorter than the others, but don't worry.
Spread out your four strands. Take the furthest left piece (red in the picture) and pull it over the inner left piece (yellow in the picture). Next, take the furthest right piece (blue in the picture) and pull it under the inner right piece (green in the picture). Now take the blue piece and pul it over the red piece.
Now start from the furthest left piece (now the yellow strand) and repeat.
(If you're confused, you can check out this video to get the idea of braiding with four strands)

When you get to the end of a strand, simply tie on another strand and keep going. Try and braid in the ends of the knot as much as you can, but don't worry if they stick out. You can always cut the ends off later. Keep going until you reach 7 yards, but these do stretch so make sure that you stretch them a little bit before you measure!

Step 3: Side Supports

Tired of braiding yet? Don't worry, you're almost done! Now it's time to braid the 20 4 yard-long side supports. Since these will be supporting more weight, we want to make them a little bit stronger than the chair body. Instead of cutting both bags into thirds, this time you want to cut one of the bags in half. Take four of the pieces and tie them in a knot. Take these four pieces and braid them like you did with the chair body.

Step 4: Attach Hooks

Divide the 20 4-yard-long side ropes into two groups. Pull 10 ropes through the carabiner so that the carabiner lies halfway through each rope and the ends of the ropes are about even. Take 3 feet of the white nylon and polypropylene rope and hold it slightly higher than beside the plastic side ropes. Bring the white rope down about three inches and then bring it back up, leaving a little loop at the bottom. Starting at the top and working downward, wrap the rope tightly around the bunch of side ropes for about two inches or until you almost reach the loop. Thread the white rope through the loop and cut any extra string off. Pull the top of the rope so that it tightens the knot and pulls the string into the knot.

For further explanation, look at the photos below or check out this video.

Step 5: Make the Back Support

Take two ropes from the right side and two ropes from the left side. These will be the back support. Leave the rest of of the side cords for later. You can even tie them back to keep them out of your way.

Measure down 30 inches from the bottom of the wrapped knot and make a square knot.
For instructions on how to make a square knot, look at the images above or check out this video.

After the first square knot, reverse the ropes so that the two working ropes (red and blue) in the first knot become the filler ropes (yellow and green) in the second knot and vice versa.

*note, the image above is a single square knot!

Step 6: Attach the Body Pieces

Direct the rope ends of the back support so two go right and the other two go left instead of letting them dangle.
Starting beside the square knots, fold a 7-yard rope in half and tie a lark's head knot (check out this video to figure out how) to attach it to the back support, letting the ends dangle. Continue to attach the ropes along the back support until you have attached half of them, and then attach the rest to the other side of the back support.

Step 7: Knot the Body of the Chair

For the first row of knots, tie square knots so they rest just below the lark's head knots in the previous step. Use 4 cords per knot (2 fillers). Tie the knots firmly, but don't over tighten them and stretch the plastic too thin.

After the first row, leave a 1-2 inch gap between square knots and skip the first and last two ropes every other row.

After knotting for 20 inches, reduce the spacing between the knots to 1/2-1 inch between knots and continue knotting for 15-20 inches, depending on how long you want the seat of the chair. If you need to lengthen the ropes, simply untie the knots on the bottom and continue braiding.

Step 8: Make the Bottom Support

Locate the ropes for the side supports you tied back in step 5.

Select two cords coming from the right side, and two from the left. Measure 45 to 50 inches down from the wrapped knot. Put a clothespin on the four ropes. Before you tie a square knot, hang the body of the chair over the bottom support and check the chair depth. Adjust the chair depth if you don't like it, and then tie a square knot. Just like the top knot, switch the ropes around, so the fillers become the working cords and tie a second square knot.

Like you did with the back support, direct the ends of the ropes so two go right and the other two head left, rather than letting them dangle.

Using a two half hitch knot (to learn how, check out this video), attach half of the ropes from the chair body to the right of the square knots, and half to the left. Start at the center and work outwards. Make sure most of the knots cover the left over rope after the square knots on the bottom support.

Weave the ends of the rope into the body of the chair. If you have a lot of rope, you can cut the rope and then weave in the ends.

Step 9: Connect the Side Pieces

Organize the side supports for the right side of the chair into sets of two. Space the side supports evenly and bring them through the edge of the chair body (look for the spaces where you skipped the the first and last two ropes while knotting the chair body) and tie an overhand knot (you know how to tie this, but you might not know it by name...here's a video refresher). Take the ends of the knots and weave them through the base of the chair.

Step 10: Enjoy!

Whoo hooo! You're finally done! Now it's time to sit down and enjoy your hard work.

Check out my other group instructable here, follow me on twitter or check out my tumblr page!

Special thanks to:
Bryan Postelnek for all the plastic bags!
TE class of '13