Trimming is the process of cutting a document down to its finished size.
Commerical printing presses cannot print to the very edge of a sheet of paper so in order to achieve this effect, your design is usually printed onto a larger piece of paper. The excess unprinted border is trimmed off after printing using a guillotine.
If you are creating artwork for print, you will need to add an area of bleed to your design which is the part that’s trimmed. If you’re not sure what bleed is, take a look at our article ‘What is Bleed?’ for more information.