As I highlighted in a previous blog post, I have been using laser cutting as a way of creating a woodcut block for printmaking. For the first time, I have now worked out a process for printing up a two colour woodcut. I created a wood cut print of carp swimming, printed up with one block in dark green ink, with a second block overlaying this in coral pink. I wanted to share the first part of this process - creating the wood cut blocks - as part of this blog post. I will follow up the actual inking up and printing in the next blog post.
The challenge with creating any multi coloured hand made print is how to achieve correct registration - that is, how do you line up the blocks you have cut for each colour, so that the image does not turn out squint? A very small degree of misalignment between the different coloured blocks in a hand made print can be very charming, and indeed, emphasises the hand made quality. However, if the coloured blocks are very out of line, the image can look crooked or even deformed. You can see above that there is a slight gap, for example, between the head of the carp and the green lily stem, and the eye does not completely line up, but these minor flaws are inconsequential.
The process I have hit upon is to create my woodcut first. I develop a vector design on Inkscape, which I then laser cut out of wood. Any potential fragile areas I rasterise - that is, I use the laser cutter to blast away that top layer of wood. To do this, the part you wish to keep in relief - that is standing proud - is set to white in the vector image. The areas you wish to rasterise, are set to black in the vector image. Then you have to remove the unwanted parts of the design - you do this by setting up a cutting line. On the laser cutter I use, this done by outlining the shape you wish to cut in RGB red at 0.001px line weight. You can now replicate this cut out design on a piece of mountboard as an engraved outline. You cut out your pieces of mountboard as the same size as your image. By engraving the outline of each of your woodcut blocks, you know exactly where to glue the pieces of wood. This ensures almost perfect registration.
You can see here that I am gluing the pieces of the woodcut that I plan to print up in green. I am lining up my pieces of wood with the corresponding engraved lines. As the mountboard is also cut on the laser cutter, it has precise right angles at the corners (if you ever hand cut right angles, even with a set square, it is really difficult to get it bang on). This method has been a successful way to create a multi coloured woodcut print with accurate registration.
The final step of this part of the process is to paint plate oil onto the raised areas of the woodcut. This is for two reasons. It slightly raises the woodgrain, so the wood effect is more pronounced; and it means the woodcut does not soak up too much ink. In the next blog post, I’ll describe how I printed these woodcut blocks up.