Hi - I want to varnish over a watercolour done on Claybord. Does this varnish work ok on watercolours? thanks x
Varnishing any watercolour can be tricky as you do not want to disturb the paint and cause it to bleed. Varnishing a watercolour will provide a permanent layer, as the absorbency of the surface used for a watercolour painting will allow the varnish to sink in and not be able to be removed at a later date.
If you would like to varnish a watercolour, then using a spray varnish very gently allowing each layer to dry thoroughly between applications is a good way of protecting the unframed painting from environmental elements like dust, humidity, and UV radiation.
Some artists will use the spray varnish as an initial fixative then if they wish they will add a brush varnish.
As with any technique you are unsure of it is always advisable to test and try on a separate piece, so you are not disappointed with the end results. Varnishing can alter the appearance of some colour which is something to be aware of.
On a personal note I will often use the Winsor & Newton Artist Picture varnishes as they offer a fine and even application. I have used on a Watercolour painting on a watercolour canvas, with no issues.
There are fixatives which have been designed to work with Watercolours:
Rembrandt Watercolour Matt Varnish (75ml) - Dries in a few hours and has little influence on the degree of gloss. This varnish does not yellow and is water resistant when dry, making the painting less susceptible to moisture. It is ready for use, do not thin and should be applied in one layer and in one direction. It is not suitable for extremely absorbent grounds.
The varnish should be shaken well before use and clean brushes with white spirit, this product is highly flammable
Schmincke AQUA Fixative 300ml Spray Can - A final fixative for watercolours, this spray protects paintings from fingerprints, humidity and dust with no colour change when applied in thin layers.