yes they do work, but on light shirts only. I would also say that the image can't be huge or not all of it will transfer, and you will get less color in spots. I just did a cars one for my son, and the image was 4x6 I would go as high as 5x7 size image, something the whole iron can move around easy on and get all of the image evenly. Last November I did an 8x8 square image and followed the directions, but some of the color stayed on the paper in areas, and made it look lighter, it did not look bad, but faded a little. Also they don't peel or crack. one more thing make sure it is a cotton poly blend, it works better. You can do 100% cotton too, but just iron a little hotter and longer. I hope that helps.