To achieve the best results from your sandcarving, you want to choose the right thickness of photoresist film. Artwork determines the mil thickness of the photoresist film. Photoresist film is available in various thicknesses for detail and blasting depth.
Detailed designs and small fonts need to be processed on the thinner material thickness such as a 3-mil photoresist film. A 4-mil photoresist film is perfect for detailed images that require a slightly deeper etch. To achieve the best results on detailed images, process them on the lower mils such as 3- or 4-mil.
-Liz Haas, Rayzist