How to make Plarn. Plastic Yarn.
Make from plastic shopping bags.
Then you can use it to create something like the purse that I crocheted out of Plarn,

You will need:
*Plastic shopping bags
*Scissors

Step 1: Flatten Out Bag

collect lots of plastic shopping bags.
flatten out the bag by pulling at both ends.

Step 2: Cut Top and Bottom Off of Bag

Cut the handles off of the top of the bag in a straight line.
Then cut the bottom seam off of the bag in a straight line.

Step 3: Fold the Bag Lengthwise

Fold the bag lengthwise in half, then in half again.

Step 4: Fold the Strip

Fold the strip in half lengthwise.

Step 5: Cut in Half

cut the strip in half at fold.

Step 6: Cut Strips in Thirds

cut strips into three pieces.

Step 7: Open Strips and Attach Together

Open each of the six strips.
Take two strips and loop them inside each other.
Pull each end until there is only a small knot.
Then keep attaching one loop at a time to the end
until you have a ball of yarn.
If the bag has a hole, that's okay. Or if the loop is not closed.
Just tie a knot so your plarn doesn't come apart.