I thrifted this big cable knit sweater last weekend. It was $5, above my usual sweater thrifting quota, but I really wanted to make a throw pillow, there was a lot of cable knit in this, and the buttons were nice. Thus, I hacked it up.
My pillow interior is down filled and 18×18, and this sweater was more like 16×16, but the knit was able to stretch enough. Really it looks more rectangular here, which is true, but it worked out. I had to take the sides in an inch on each side because you can see that I had to hack the top a little above the armpits.
I did a 3 length zigzag stitch for the seams. Knitting goes through the sewing machine pretty slowly, so I think it’s held together quite well. I did all four sides, and the buttons are on the middle of one side of the pillow for opening/closing. I ended up tacking and hand sewing between the buttons because there was a bit of gaping due to stretching the material, but now you can not tell.
P.S. The pillow is on the living room couch now.