T-Shirt yarn rug

Well, I finally finished my back hall rug made of t-shirts. Because it was going to be used for a utility area where the big dogs thunder through to go outside, I didn't bother cutting the t-shirts into nice strips, I just tore them into about 1 1/2 inch strips. First, though, I cut off the bottom edges and set them aside. I pulled off any peeling plastic from iron-ons that I could, those that I couldn't I cut the shirt off even below. I left stains that didn't come out in the laundry, paint, printing, bleach marks, and any color unevenness, they just added to the design as far as I was concerned. I didn't worry about the weight of the shirts, I figured it would be pummeled so much a few ripples wouldn't matter.
To keep it from having huge ripples from uneven "yarn" sizes, every so often I added a row of two of a stretch double knit salvaged from an old stained house coat of my mother's (the light blue in the closeup) as well as a few other double knits. Those I cut into roughly 2' wide strips because they were so light. I just cut the material in spirals, and if there was a corner, I didn't bother rounding it. I also fudged the number of stitches, adding one here, or skipping one there. I didn't mind ripples, I didn't want waves. I used a single crochet and a Q hook. When it was as big as I wanted, I used the set aside bottom edges of the shirts for an edging all around.
It took a lot more t-shirts than I thought it would, in order to finish it and keep it a free project, I had to beg for stained and tattered tees from co-workers. That worked too well I fear, because now I have a stash of tees to make something else out of. It seems that everybody has tattered and stained tees laying about, and this way they can get rid of them guilt free.
If you decide you want to make a rug out of t-shirts, and you want it to lie flat, you need to cut your yarn evenly. There are several ways to do this, and some good video tutorials on the net. The way I do it if evenness matters is to use a quilting guide , the kind with the square measuring marks, and a rotary cutter. First cut off the bottom hem and across the chest just below the arms to make a tube. Slip the guide into the tube and line up the bottom edge of the material with one of the lines. Make an angled cut across 2-3 squares and up to the width you want your yarn so that your leading edge has an angled point. then cut across at the measure you want, 1, 1 1/2, 2 as many times as you can fit. Turn the tube of cloth and continue the lower cut around, angling it at the ends to join with the next strip so that you have a continuous strip. With careful cutting you can have very even yarn. Roll it into a ball, giving the yarn a good yank to stretch it. As it rebounds, the edges curl in, making a very neat, round yarn. When you have finished your rug, paint the back with latex to make it slip resistant, or you can coat it with rubber cement. Because nothing short of gluing the rug down will hold it in place with these dogs, I did neither, but it really doesn't slip underfoot at all.
BTW, the cut off parts of the shirts shall not go to waste, I am cutting them up to make a rag rug. When I get that done (in however many years from now) I'll let you know how that works.