To be able to stencil a small series (up to 50 pieces] for use in schools, project instruction, etc. No investment, no skills necessary, results in an acceptable quality print.
A stencil machine is mechanically complex. Working with a stencil machine asks for plenty experience, In many ways it can go wrong, such as the transport of the paper through the machine, the right amount of ink, the proper fixation of the vulnerable thin stencil on the rotating drum.
Yet the stencil machine was popular, before the cheap photocopies became available. The reason is: cheap prints and printing can be done under one's own control. So ideal for schools!
However there exists an alternative, the stencil board. Its use could be seen on television during the student uprising in 1989 at the Tian'anmen Square. The Demotech design is based on this stencil board. It trys to solve the problem of materials needing to be of a special quality to make stencilling possible. Also preparing and producing prints should become easier to learn.
The stencil machine is replaced by the stencil board: a flat panel [A4 size or larger], underneath an ink cushion made from fabric and the stencil. Paper is put on top of this under a smooth piece of cloth and printed by rolling a piece of tube over it. This stencil board can be made DIY-style and gives acceptable performance in numbers and quality. Re-inking after 50 prints.
Stencil printing is achieved because of the stencil sheet is made porous by damaging the layer of wax on top of the sheet. This can be done with a pencil, with the hammers of a old fashioned type writer and best by the needles of a needle printer.
Regarding actual printing (stenciling) good control over contact time and contact pressure is essential for a good quality copy from the stencil on to a sheet of paper.
With the Demotech design rolling a short piece of smooth PVC-pipe over the board, as illustrated, does this. The stencil board can be made from hardboard. A glass plate is used as a flat base.
The printing is done as follows:
- Ink is applied evenly on a soft cloth covering the glass plate (size the same as the stencil).
- The stencil is neatly stretched over the ink cushion and fastened at both ends by detachable board strips.
- A sheet of paper is positioned on the stencil.
- A second soft piece of cloth is put on the paper. For ease of operation this cloth is fastened at the top end of the board.
- A short piece of PVC-tubing is placed against the top ruler of the stencil board.
- With a pressure pad, held under one's arm, the pipe is rolled with even pressure and even speed over the stencil.
- The sheet of paper, now with the print from the stencil, is taken out and a new sheet is put back.
- After 50 copies the ink cushion should be inked again. These 50 copies can be made in about 20 minutes.