MITRA Forum Question Details

I understand from another forum that you are asking for a material to cut the absorbency of the gessoed panel before the application of a gilding oil mordant. I know many gilders who apply shellac and let it dry before applying oil mordants to absorbent surfaces. This is probably the most common practice today. The use of shellac in fine art does not go back that many centuries, though. I have also used applications of egg water and even glair to cut the absorbency of gesso and sections of egg tempera when I have added fine gilded details to an egg tempera reconstruction. I would bet that an initial “size” coat of oil mordant would also work but I would want to make sure that it thin enough that you worked quickly and make sure that you did not get textural overlaps. I would guess that shellac would be the most common material for this. We have contacted a few others who will likely have something to add.  

​Koo is ertainly correct about the fact that there mordants  that can be applied in an aqueous system. There generally dispersions based on acrylic resins which dry water resistant. I understand from your post on another formus that you were interested in sizings for oil mordants.

​As to the question of Oil Size, preparation is paramount when one considers the amount of time that goes into a gilded work, whether Frame or Icon, what is important is allowing the proper drying time for the materials; for example, the temperature and drying will always vary depending on the humidity in a room. I try to gild on low humidity days and specially in the summer the room should be in the low 70’s with very low humidity. If we are working with Oil size as to Water Gilding, I use Rolco or Kemp Burnish Sealer which is a primer/sealer as to Shellac and after 2 to 3 coats directly over the wood or real gesso, not latex, it really hides many imperfections in the wooden surface. The Burnish Sealer comes in a few colors (Red, Ochre & Gray), and after 24 hours I then apply my size. I use many different brands from Kurz-Hastings or Rolco Quick Size, this always depends on the size of the project and the working time needed, obviously a large project will require a greater working time. The wonderful quality of Burnish Sealer is the final product after the gilding and with minimal rubbing the burnished finish is quite nice and can receive a Casein Patina if desired and then a final Rolco Acrylic Top Coat or Ronan Clear Overcoat Varnish. Obviously I stated a few manufactures of various materials but all Gilding Suppliers have their individual companies they represent, so if you cannot get something from one company another’s product is just as good, for example I also use LeFranc & Bourgeois products from Charbonnel.
Martin Kotler