This information is reprinted from the Cranberry Corner column of Hand Papermaking Newsletter #57 (January, 2002).
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Each end-use for handmade paper dictates the surface texture, or sheet finish, required. The particular taste of the artist or artisan who uses the paper also has a large bearing on whether the paper used is Rough, Medium, or Smooth.
For example, calligraphers who use sharp pens do not want to use a Rough paper that would catch the pen and spoil the lettering. Therefore they would prefer a Smooth sheet or perhaps a Medium finish. On the other hand, if they are using felt pens or air brush, the sheet finish is not as critical.
A watercolourist may want to use a Rough surface in order to allow the white of the paper to show through the paint, although they usually use a Medium finish. The finish of watercolour paper is often defined as Rough, Cold Press, and Hot Press in reference to the original processes used to achieve the finish.
A pastel painter usually wants a paper with “bite” in
order to take the chalks well.
A letterpress printer could use all three finishes since the raised type pounds the ink into the sheet with the high impression pressure. Thus the printer can attain good print reproduction even on Rough paper.
On the other hand, a wood engraver usually wants a Smooth sheet for low pressure dry printing, although Medium and even Rough paper can be used if the engraver is prepared to moisten the surface of the paper before printing. The moisture softens the surface and permits much better printing fidelity.
Normally a printmaker likes to use a Smooth paper in order to obtain good print reproduction.
A marbler usually uses a Smooth or Medium sheet for good transfer of the dyes from the bath to the paper surface.
Thus, the hand papermaker must be prepared to offer all three finishes to satisfy the particular needs of his clients.
How is this achieved?
ROUGH. After couching the wet sheets onto the press felts, the “post” thus formed is dewatered under high pressure in the wet press. During this procedure the wet paper is very soft and its surface takes on the surface texture of the weave of the wet felts above and below.
If the wet sheet is allowed to air dry (loft drying), the impression of the felt weave remains in the surface of the paper and results in a Rough finish.
MEDIUM. A Medium finish is achieved by stacking the wet sheets one of top of the other on a smooth, flat press board, as they are removed from the wet felts, taking great care to make sure that each lies squarely on top of the previous sheet.
A smooth top press board is then set in place and the stack of wet paper is put back into the press. The top press platen is lowered very carefully and a very low pressure is applied to the stack.
If too high a pressure is applied, the stack may “block,” making it impossible to separate the sheets. It may even “extrude,” thus destroying the paper!
The stack is then removed from the press. The sheets are then carefully separated, by teasing them apart with a spatula, and draped over the drying rack as described in my previous column (October 2001 Newsletter).
SMOOTH. To attain a Smooth finish the dried Medium sheets are passed through a “calender.” This consists of two driven horizontal steel rolls with adjustable pressure between them, similar to the press on an old washing machine.
In order to protect the paper from any dirt or roughness on the roll surfaces, the paper is placed between the smooth surfaces of two sheets of Masonite and the whole sandwich is fed through the calender.