Nowadays the shellac you come across is usually in a nail bar. Here we are looking at a different material – the original shellac. Find out why this is a really useful varnish and sealant for printmakers, particularly when making collagraph plates.
Shellac is a natural resin secreted by lac beetles living on trees in India. It recorded use dates back over 3000 years, and it was used for a multitude of purposes until the invention of plastic mostly replaced it.
Nowadays it is used in wood finishes, you may know it as French polish, knotting or sanding sealer.
‘Shellac’ nail varnish is not made from beetle secretions but is a trade name for a synthetic polymer product – I am sure it could have some use in printmaking but here we are concentrating on the original and natural beetle shellac.
What do printmakers use shellac for?
It is particularly useful for sealing collagraph plates, which are made from a mixture of collaged materials and often include pva glue.
Pva glue (or Elmer’s glue if you are in the USA) tends to stick to damp paper when under the pressure of the press, this means your prints will tear when you remove the paper from the plate – they are completely ruined, but shellac will seal the pva and prevent this from happening.
When should I use it?
Shellac seals the surface of your plate without changing the texture because it is so thin, I have found that modern varnishes, (acrylic, polyurethane etc.) are too thick and will clog up the textures in a collagraph plate, but if you cant get hold of shellac use these alternatives and thin them down.
You only need to apply it to areas with pva on them because of the sticking problem, but it will also protect the whole surface if you are using delicate materials. I avoid putting any on very smooth shiny areas (e.g. parcel tape), as it will roughen up this surface and print slightly darker.
How do I use shellac?
Shellac comes in the form of thin flakes in a lovely rich orangey brown colour, these are dissolved in meths. I love the combination of the colour of shellac flakes with purple meths.
Sprinkle a few pinches of flakes into some meths in a jar and give it a shake, in an hour or so it will have dissolved and be ready to use.
Cover the jar up otherwise the meths will evaporate – it is best to use a plastic snap on lid, screw tops can get stuck down with shellac.
Mixed up shellac does not store well, after a few months it may not set properly and stay sticky. Buy dried flakes and mix up small amounts to use as you need it.
A brush with nylon bristles works best, it will need to sit in the liquid for a bit to let the old shellac on it soften.
Once it is painted onto a hard surface the meths evaporates and the shellac forms a layer of varnish, it dries quickly, your plate can be printed in an hour or so of being varnished but it is best to leave it longer if you can.
Things to watch out for
This shellac seal is ‘reversible’; it will re dissolve in meths so can be removed, however the meths will mess up the pva underneath so its probably not worth doing this.
See the post ‘print an ants nest’ for examples of an interesting reaction between shellac and pva.
I use a single coat of shellac as putting a second layer over the first causes a reaction that makes the surface rough, this is bad – it will affect the tones in your print making everything go dark. If anyone knows why this reaction happens and how to avoid it please let me know……
Where to get shellac
Get your shellac flakes from Hawthorn Printmaker’s Supplies.
Get your meths from hardware or DIY stores like B&Q Depot.
I like the thought that I am using a traditional material with a long rich history, and also the fact that this natural resin provides the best solution to sealing pva on collagraph plates. This meeting and mixing of ancient and contemporary materials is very satisfying.