No problem printing 35mm negatives using a 60 x 60 millimeter enlarger. The enlarger lens used for the 6 x 6 is usually a 75mm or 80mm. If you choose to use this lens, you might find, the degree of magnification provided is not enough. In other words, when attempting to make big prints, you likely will find the enlarge will be maxed out and thus won't allow. The remedy is to mount a 50mm enlarger lens. This focal length will do the trick. When buying a 50mm, find out what lens board you will need. We are taking about the female threads matching the lens you choose. Also, the 50mm lens placement will be closer to the negative than the 75 or 80mm. Often a recessed lens board will be required. In other words, do your homework, 50mm lens, matching threads and proper lens board. You will be OK if you buy wisely.