Shrinky dinks seems to become a little thinker when it's been shrunk, than Graphix film but Graphix Film shrinks with less problems. Even if it curls up, it separates more easily, and with less distortion. Both brands have printable versions, but Graphix is printable on both sides, I work mostly with the printable version since I do a drawing and then scan it into the computer. I can hen draw ad paint over the printout before I heat treat the film.
Both brands come in clear, matte clear, white and colors. But Shrinky Dinks has an extra think version I would love to use more if the surface wasn't so slick. I can sand it, but it would be even better if it were printable too.
I use a heat tool to shrink the film, not bake it in an oven. More working tips in a fwe days.