I have noticed that there are many plastic grocery bag yarn or “plarn” projects on YOUTUBE and here in Instructables. Usually the yarn is made by either cutting the bags into loops and then daisy chaining them together to form a chain of loops or they make cuts part way through the bag leaving loops that are attached to a “backbone”. The backbone is then cut diagonally from one loop to the one next to it to form a long slightly zigzagged ribbon. It seems that people are doing it that way because they think that making a straight ribbon by spiral cutting the bag is hard to do. Actually it is easier than you think.

With the right set up it is simple to spiral cut a plastic bag so that the ribbon is straight allowing you to make consistent plarn. And the ends can be spliced together so that the splice is invisible with no knots.

Let's make some plarn together so you can see what I mean.

First let me define some terms that I use so we both know what I'm saying.

Top side/Bottom side: When the bag is laid out on the table the side that is on top is the “Top side”, the bottom side is the “Bottom side”. That distinction will be important later.

Cut: When we make a cut from the start-cut mark to the finish mark, that's one cut.

Supplies

You will need: Very sharp scissors, 3 by 5 cards or something to put marks on. Painters tape works too. Also an Exacto knife or equivalent and of course, plastic bags.

Step 1: Alignment Marks

As I am sure you know, in order to cut a spiral, as in a barber pole you need to cut at a certain angle. The alignment and cut marks are used to establish that angle and guide the cut. To make those marks, I used a 3 inch by 5 inch card but you can use whatever you like. I want a 2 inch wide ribbon so the marks are 1 inch apart. As you can see from the picture, there are three marks on the top and one mark below . Cut in half so that the top half has the 3 marks and the bottom has 1. Here is what the marks are for.

Top middle mark: This is where you put the upper left corner of the bag to do the first cut. It's used only once per bag.

Top left mark: This is where you put the upper left corner of the bag for the second and the rest of the cuts.

Top right mark: This is where each cut ends.

Bottom mark: This is where all your cuts will start. It is placed directly below and in line with the top middle mark.

The left and right marks are the width of the ribbon you want. Since I am making a 2 inch wide ribbon, the marks are one inch apart. The width you want may be different so adjust accordingly.

Step 2: Placing the Marks

Place an already cut grocery bag on the table and position the marked cards as shown. Tape them down so that they don't move. If you are really good at making straight cuts this is all you need to get started. I am not, so I added a line from the cut starting mark to the cut ending mark so I could follow the line and make a straighter cut.

Step 3: Start of Cut

This picture shows a bag aligned and ready for the first cut. If you find starting the first cut a bit difficult, place a piece of cardboard between the top and bottom sides near the start mark. Then use an Exacto knife to cut the first 4 or 5 inches of the cut. Now you can grasp the cut end and hold it as you use your scissors to make the rest of the cut. The next picture shows the completed first cut. You may find that using a weight near the finish cut mark will make the cutting easier.

Step 4: Flip

Flip the bag toward you top to bottom. Make sure you align the top left corner with the top left mark and the end of the cut you just made with the cut starting mark. The start of the ribbon will go off the table.

You will notice that the widest part of your new ribbon is just half the width that you want. That's OK. This next cut will bring your ribbon to full width.

From now on all your cuts will be the same. Continue flipping, aligning and cutting until you finish the bag.

Step 5: Finished Ribbon

You will end up with a ribbon like this.

Step 6: Be Careful!

Caution! Make sure at the start of each cut that your scissors are not cutting both top and bottom sides together. You want to cut the top side only. It is only too easy to miss that and cut both and ruin your emerging ribbon.

Step 7: Permanent Guide

If you make a lot of plarn you can make a permanent guide that you can keep in your closet until you need it.

Step 8: Splicing

If you mark the place where the starting taper ends and the full width starts on both ends, it will be easier to splice the ribbons .

If you are spinning your ribbon into yarn, when you get to the mark where the ending taper starts, wrap the end of the spun ribbon around the start of the taper of the next ribbon for a few inches. After you spin those few inches, then wrap the tapered end of the new ribbon around the end of the spun ribbon. Make sure that the tip of the ribbon is safely in the fold of the new ribbon. Since the narrowing taper of the end of the ribbon is offset by the expanding taper of the next ribbon, the diameter of the yarn will stay the same. The splice will be invisible. What is nice is you can now use this yarn in a weaving loom with no knots to get stuck in the heddles.

If you are a fan of plarn try this and see if this is easier and straighter than other methods of making plarn.