I want to print 16x16 on my Focomat IIc but my 100mm lens will only go to about 12x12. Obviously, if I use my 60mm lens I will be able to go bigger. What are the drawbacks to using the 60mm lens for 6x6?
Unless you have a Wide Angle 60mm lens, you won't cover the format. I'd look for the Rodenstock 60mm f/4 Rodagon-WA Enlarging Lens.