Set up two identical USB printers
You must be looking for Printer classes (No, not school)
Firstly disconnect both the printers.
Open "Printing" and you will be presented with such a window:
Press the Plus and select Class:
Create a new class:
Add the right printer to this class:
Repeat this process again for the other printer, If you have done this correctly you will get two new printers in your window, like this:
With one and two being the new classes. You will now me able to print to both the printers.