This stuff is effectively pastel pigment in a handy dandy box with an applicator and colours that are designed to work together. You will need to clear cote over it to seal the colour on to the model once applied, but it's simple and very effective to use and gives great results if you just start slow and take your time. And you can just wipe it off if you make a mistake. I used mine to give rocket bells that heat scorched look. TIP: Go buy a pack of sponge eyeshadow applicators and use one for each colour as the applicator with the kit will get pretty gungy pretty quick.
