It would be interesting to see what feedback this warrants. I am talking about 35mm format here: Is the enlarged image quality best served by 1) allowing a glass plate to touch the top of the negative and thus keep it flatter (at the real expense of introducing some possible 'in focus' dust) or 2) is it better to be able to use a traditional negative carrier in which nothing touches either the top or bottom of said negative (thus allowing a slight curvature to result on the top of the negative)? The Leitz Valoy and the Durst M301 utilize the first design and most other enlargers (especially Japanese) utilize the second design. Personally, I cannot find any comfort using the first as the introduction of that other surface to keep immaculate greatly bothers me. The slight curvature that might result from not allowing any glass to touch the upper portion of the negative can be greatly mitigated, even eliminated, by stopping the enlarging lens down. But is there any real validity to the first approach that I am not seeing? I recently turned down an enlarger (Durst M 301) because of this. - David Lyga.