Varnishes for gilders – the wish that will not come true
Varnishes for gilders are designed to protect gold leaf and metal leaf against scratches and oxidation and remain invisible to the eye. Unfortunately, such a varnish will never truly exist.
Varnishes alter the colour of any type of gilding – whether gold leaf, silver leaf or metal leaf. The varnish coating always causes a refraction of light, which prevents the direct reflection of light on the metal surface. With a varnish coating we always get a slight colour change and loose the original metallic character of the gilded surface.
Protective varnishes find their justification when used with metal leaf and silver leaf. Surfaces covered with metal or silver leaf would oxidize in a very short time without a protective varnish. With real gold leaf there are only very few reasons or occasions that call for a protective varnish. Gold leaf with a fineness ranging from 6 to 21 carats would oxidize over time without the use of varnish. From 22 carats upwards, a coating on interior gilding is not required. Exceptions can be surfaces exposed to heavy wear, e.g. gilded picture frames, gilded grandfather clocks, gilded door elements and door frames.
No varnishes on exterior gilding
Careful consideration must be given prior to applying a protective varnish onto gilded surfaces in outdoor spaces. The layers of oil gilding does not provide suitable hold for a coat of varnish. The varnish runs the risk of cracking and breaking off. Varnished gildings exposed to the weather generally become worn and unsightly after a few years. A gilding without a lacquer coating will last 5 to 10 years longer in this case.
There may be justified exceptions where the use of varnish on external gildings would be favourable. The rapid damage caused by mechanical stress on gilded entrance gates and doors poses a problem for the gilder. A protective varnish can delay damage to the gilding. Provided the varnished gold surface lasts longer than the unvarnished surface, there is much to be said for this alternative.
Unfortunately, there are plenty of bad examples of varnish having been applied to wayside crosses and weathercocks, albeit with the best of intention. Due to their “protective coating”, these gilding works are not able to survive and appear to the observer more like a coat of paint.
We offer a small number of carefully selected varnishes to choose from.