I ordered two sets of the gelatin scars, and had a practice run with one set today.
They glued on easily and are quite comfortable.
The only problem I have is the line between my skin and the gelatin. When I begin to apply make up, the join becomes very noticeable. I've got water based red, which took nicely. For the white I've got Leichner Theatrical Clown White.
The gelatin is different to my skin, and I'm concerned it's going to be really obvious. I used the gelatin blender, and it did help a fair bit, but I must be missing something.