Why do some transparent areas of my layers import with “blotches” that don seem to exist in the original Photoshop document?
It is possible to create invisible “residue” as a by-product of certain processes in Photoshop, for example: using the eraser to delete part of a layer while the eraser is not set to be fully opaque, use of the Paintbrush tool set to an opacity less than 5%, or failing to delete all of a previous selection that was created using very diffuse feathering, among others. Since most monitors will not display the difference between full transparency and color opacity of less than 5%, you will not be able to see this residue on the screen, but it exists in the file nevertheless. As mentioned above in the Technical Note under the Anti-Alias option, Photoshop uses a secret “alpha channel” to track the transparency of all pixels in the layer. When PhotoCaster’s Anti-Alias option is checked, it interprets any pixel in this alpha channel which includes these residual almost-transparent pixels as well as pixels legitimately requiring anti- aliasing as needing to be anti-aliased to the colors in the
