Position in the vector where the new elements are inserted.
What have you?
You are inserting into vector v2[number-1]. That is entirely separate vector from the v1. It might have been created by copy construction from v1, but that is all.
Therefore: v2[number-1].insert( v2[number-1].begin() + location, element );
1) You don't show how you derive printers, but if it is the number of vectors you want to insert, you're going to insert one vector too many. The condition should be i<printers.
2) You're inserting the same vector into v2 each time the loop runs.