Mould-Made Paper
The
earliest papers were hand-made by dipping a rigid wooden frame with a fine wire
mesh into a vat of ground up cellulose (cotton or wood) fibres and water. The
fibres in the resulting sheet would be arranged in a random fashion. This would
mean there were no significant differences in properties of the sheet, in the
long or short direction, and the sheet would be very strong and stable.
At
St Cuthberts Mill our cylinder mould machine is one of only six producing
artists paper, and the second widest in the world. It replicates the hand-made
process but in a continuous operation. The resultant sheet has only slight
differences between the long and short direction. This means exceptional sheet
stability.
We
have a cylinder around which there are 3-joined wire mesh frames. These lift
the fibres from the vat to form a sheet that is joined to the next sheet and
therefore continues down the machine. This strip of paper then passes through
natural woolen felts that both add surface texture and remove water from the
sheet.
The
paper passes through a number of cylinders full of steam that dry the sheet.
This dry paper then passes through a bath where any surface sizing (e.g.
Gelatine) can be added. If it is going to be a smooth paper it will pass
through the calendars (hot press) after final drying. The paper then proceeds
to the reel up where it rolls up on a cardboard core.
In
the case of four deckled edged sheets this reel of paper is then split and
inspected by hand, in a department called the 'Salle'. We have photos dating
from the Edwardian era that show very little has changed!
Mould-made
paper machines produce paper very slowly and that is why it is often more
expensive, but it is a far superior product. Machine-made or Fourdrinier machines
produce larger quantities of cheaper paper at high speed using lower quality
pulp, which show marked differences in properties between the long and short
direction of the sheet.
