QUESTION: What is a master document in a variable-data-printing workflow?
ANSWER: In a variable-data-printing workflow, the master document is the document that contains the text and graphics that are the same on each document in a print run.
If you're using software that's designed specifically for variable-data printing, and if you're using a printer/RIP that's geared for variable-data printing, your software will be able to download the master document to the printer/RIP only once (as opposed to downloading it to the printer/RIP over and over, once for each variable-data document in the print run). This will allow your variable-data documents to print faster than they would otherwise.
A variable-data-printing workflow that allows the master document to be downloaded to the printer/RIP only once is sometimes referred to as a "print-optimized" workflow. For more information about print optimization, click here.