Stardust from outer space!
Carborundum is a form of stardust originating outside the solar system.
It was discovered in a meteorite that landed in Arizona.
Because of its interstellar origins it is very rare and only minute amounts of natural carborundum exist here on earth.
Its nice to remind yourself of this exciting and romantic history, which is little known now it is manufactured here on an industrial scale.
Carborundum made on earth
Luckily you don’t have to wait for a meteroite: this useful material is made by combining sand and carbon at very high temperatures.
Known as “silicon carbide”, it is generally used as an abrasive (eg wet and dry sanding papers) or for sharp cutting edges on tools like saws. You can also come across it as grip tape on skateboards and other slippery surfaces.
The carborundum printing technique was invented in the 1930s. This basically involves glueing or painting carborundum powder onto a printing plate and inking it up with the intaglio process. The gritty surface holds ink and produces prints with strong colours and tones. Prints made in this way can have a very ‘painterly’ quality.
Several forms of carborundum are useful for printmaking:
Powder, Paint and Paper.
You can use silicon carbide (“carborundum powder”) or aluminium oxide (“emery powder”)
It comes in different grades generally fine medium and coarse. If you are not sure which to get I’d suggest fine to start with.
The powder is non toxic but fine dust can irritate eyes and lungs, so take precautions to avoid it flying around everywhere.
You can buy it quite cheaply from hawthorn printmaker, or other printmakers suppliers.
For a home made version mix carborundum powder with pva, wood glue or acrylic paint. Wherever you paint it on your plate you will get darker tones.
You can also buy ready made paint This is wonderful stuff! Very easy to use, needs no sealing, sticks to any plate surface.
It is an acrylic paint which is loaded with carborundum powder. I stumbled on it by chance while looking for other paint and am surprised to find that other printmakers don’t seem to have discovered it – yet!
When it is dry (doesn’t take long) it will not re-wet and stick to the printing paper in the press so it doesn’t need any shellac to seal it.
Also called “wet and dry paper”, it is used to get a smooth finish on surfaces like car body panels before painting.
When you stick it onto a printing plate it provides a flat even texture and is good to use as a base layer.
Wet and dry comes in different grades which are described by a number that refers to the grit size. This represents the number of holes per linear inch in a sieve screen – they range from 40 (very coarse) to over 400 (very fine).
40 – 60 = coarse
80 – 100 = medium coarse
120 – 150 = medium
180 – 220 = fine
240 or more = very fine
The grit size and grade are stamped on the back of each sheet. Sheets are normally 280 x 230 mm
I find a good source of wet and dry paper is Poundland where you can buy packs of different grades for £1.
If you would like more info on the technical aspects of carborundum production this is a good website; http://www.tygre.eu/cms/project/production