The Scovill Printing Frames for Photo-Engraving.
The Printing Frames made by the American Optical Co. for photo-engraving are like everything else manufactured by this factory, of the highest degree of perfection, and the utmost care was given to the comparative distance of screws so as to produce an even pressure. Many negatives have been either ruined or snapped by the use of imperfect Printing Frames.
The American Optical Co. Printing Frames for photo-engraving are the only safe ones on the market.