Mackle

An imperfection in the printed sheets, part of the impression appearing double. If the frame of the tympan rubs against the platen it will inevitably cause a slur or mackle. This is easily remedied by removing the obstacle so as to clear the platen. The joints or hinges of the tympan should be kept well screwed up, or slurring will be the consequence. When the thumb-piece of the tympan is too long it always produces a slur: this can be prevented by tiling off a part of it. Loose tympans will at all times slur the work, and great care must therefore be taken in drawing them perfectly tight. The paper drying at the edges will also slur; this may be remedied by wetting the edges frequently with a sponge. Slurring and mackling will sometimes happen from other causes; it will be well in such cases to paste corks on the frisket, or to tie as many cords as possible across it, to keep the sheet close to the tympan.