Workshop – wivenhoe printworks

Saturday saw our first post-lockdown Printworks course with day one of ‘Intro to Carborundum Printing’.

The ‘Carborundum’ process (developed in the 1930s and onwards) is in essence the application of a mix of thick ‘impasto’ (paste) acrylic binder and Carborundum powder (very fine hard Silicon Carbide grit) onto the surface of a metal or plastic printing plate. The mix is worked and spread out on the smooth surface of the plate, allowed to harden over 24 – 48 hours, then inked and printed as a deep intaglio collagraph print. The results are often unusually stunning with their rich tones and their capacity for creative colour inking.

The Carborundum powder creates an amazing range of textures which have great capacity for holding ink. The thickness of the mixture, hardness of the grit and effects of brush or scraper to create marks and strokes in the mix all contribute to a very rich and varied inking surface.

Printing these plates onto well-dampened rag paper under a high pressure etching press results in a very striking range of ink tones together with an incredibly lively print texture. The toughness of the grit/binder mix allows for medium editions with good plate life: editions of between 10 and 30 are often very successful and retain great freshness of tone and texture.

Pre-mixing the ink (usually oil-based etching inks) with a very large proportion of oil-based extender allows under-colour to show through and creates some stunning colour mixes with two to four colour plate printing.

In this two-day intro course we will explore the practical and creative use of this versatile and tactile medium to create some large, lively and very expressive prints.

This two-day course is now fully booked up but we will definitely be running a further weekendnder or other two-day Carborundum course in the very near future. Please get in touch if you are interested in this enjoyable and very versatile print process!

Programme:

Day 1

Principles of textured collagraphy
Overview of the Carborundum print process
Examples of Carborundum prints
Some images inspirations (sketching for Carborundum *)
Grit size, consistency, ways to apply the Carb/Gel mix
Using templates and light box
Spreading, combing, brushing and gestural forms
Stencils, silk screens and pressed-on textures
Gel viscosity and water content: working wet and dry
Curing our plates

The first day will start with a review of how Carborundum printing relates to other intaglio work and what makes it such a rich and enticing process…

We will look at the main stages of the process from prep to plate to print so we see where we might be heading…

Then we start mixing up our gritty gels and making sample plates of our own using brushes and spreaders: getting a feel for the material in its sticky state, celebrating its adhesive and drying qualities.

As the day progresses we will experiment with different ways to apply our gel surface, making brush and spreader marks with it.

We will go on to use masking tape, paper /film stencils (plus old silk screens) to create and shape areas of even, almost ‘mezzotint’ tone.

We will see how to manipulate and mark into these slowly drying surfaces to create drawn or impressed images, patterns, textures and tones. And we will see how useful it can be to have a lightbox so we can work over a base drawning or photo, manipulating, working up and wiping off areas of the sticky grit gel before they dry.

By the end of day #1 we should have a very interesting array of small test plates plus a couple of bigger plates that we will dry and harden ready for some enterprising inking-up and printing when we hit the second day!

Day 2

Plate handling
Ink and extender
Inking up/blotting off
Paper, wetness and press pressure
Overprinting
Hybrid print processes
Cleaning up

We start day #2 by handling and looking at our cured plates.

Carborundum plates have a very dense texture. This means they take up masses of ink. They also have a slight relief surface. So inking up with pure etching inks would normally cause our plates to stick to the paper and even tear its surface off.

Pure etching inks are also very rich in pigment, so it’s important to mix up our inks with LOTS of extender. A safe recipe is 20% ink to 80% extender (even 10% ink to 90% extender). Mixing hint: start with a FINGER of extender and add a TINY bit of ink at a time! The extender loosens the ink, makes it more translucent and prevents paper surface tear.

We will make up some coloured inks as well as blacks. One great beauty of Carb printing is its capacity to overlay two or three translucent layers of saturated colour on top of another. We mix up and apply our extened inks, blotting off the surplus, rubbing in and then wiping around our textured areas. In this process we use a lot of tissue to blot off the ink, rag (to wipe clean the clear areas of the plate), and we use CLEAN scrim (unlike in some metal plate inking) to wipe in and off our ink .

We will proof our test plates, experimenting with colour and tone overlays, printing multiple plates in quick sucession to avoid paper dry-out and registration issues.

With our larger plates we will fine-tune paper moistness and press pressure, making two or three-colour prints.

And we will if time permits try combining our Carb plates with simple monoprints or quick drypoints for some interesting hybrid effects…

By the end of day #2 we should have achieved a range of test proofs and produced some very saturated colour/tone overlay prints showing the rich surface and translucent colour results typical of this very tactile deep intaglio process.