Masking files are black and white images that show what areas on the cards will have a certain type of add-on. Here’s an example of what masking files look like:
From left to right, there is the actual printed artwork, a mask for the embossing, and a mask for spot UV. With these files, the Silkcards logo will be embossed with spot UV, while the wordmark “SILKCARDS” remains flat with spot UV.
You can include masking files either as separate layers in your artwork, or you can attach a different file for each mask.
It really helps to have each mask labeled according to what kind of add-on you want it to be. If we’re not sure what add-on the mask is showing, it may add time to the proofing process.