Step One: Prepare the bags
Flatten bag and fold in half vertically.
Cut off handles and bottom and cut bag in half horizontally.
When I’m cutting up a lots of bags for a project, I prefer to cut them all up at this step before moving on to next step. It goes faster for me to have a pile of bag slices.
Step two: Cut into plarn
I use a bungee cord in my closet to hang a piece of the bag horizontally. A paper towel holder also works very well. If you try to cut a whole bag at once, it doesn’t spin as well.
Then I cut it like this:
Make 1 snip, then pull strip with hand while holding scissors steady. The bag will spin on the bungee cord. Depending on quality and condition of plastic, you will have to adjust the speed and scissors position. It takes a little practice. The strip width is usually about ¾ inch (2cm).
Step three: Roll it into balls of plarn.
Usually I double the plarn when I crochet a bag, so I roll it that way after cutting it.