When ordering special effects like Foil or Spot UV job, You will need to include a second file in black and white along with the regular full color file.
Black and White file (this sample will be silver foil)
Sample with special effect added to print file
The Black and white file will be used to show where the special effect (Spot UV, Foil, Embossing, Etc) will be placed. You will need a spot file for each special effect and for each side of your print job.
Use BLACK (100% K) to indicate where you would like the special effect. White areas will not have the special effect.