The gesso being used in these videos is the Liquid Gesso that we offer for sale. The purpose of these demonstrations is to provide the user with some helpful hints when using a slaked plaster based gesso. Whether its the original Cennini formula from the 14th century or this liquid gesso. Certain facts MUST be taken into consideration. Because we are dealing with a plaster based gesso, the drying tme occurs almost immediately upon application. Usually 9 seconds !
Therefore, the object is to PUDDLE the gesso, to keep it wet, and get that raising. For me, i find the gesso manageable when the gesso has dried fairly flat. Having a high dome on the gesso may require an entire day before the gesso is actually dry on the INSIDE. Gesso is like a turtle. hard on the outside , but soft on the inside. One needs to be mindful of the drying time.
I use a dip pen and NEVER a brush with any plaster based gesso. The problem is that the hair follicles cause air pin holes and sometime the hairs themselves fall onto the wet gesso. If you need to make a fine line, use a pointed pen and a dip pen . I use a Parallel pen for all my demonstrations and if necessary to get a specific thin on a letter form, a pointed pen or a ruling pen is a very handy alternative then a brush.
Gesso feeds unto itself. Via capillary action . This is probably one of the biggest reasons for failure on the part of the user. Not enough gesso is applied to the letter or ornament or both. When dried, the gessoed item is so flat that not enough material allows for the Gold to adhere when one moves into the gilding process. Gold is attached by an adhesive that is mixed in the gesso when first prepared.
Raised gilding is a 3 step process. The first is the preparation of the gesso. Which is actually done for you. Even if you decided to make your own, the process needs to be chemically sound. Once prepared PROPERLY, we move into the second phase , the application process. Here you can apply the gesso. Once dry, you can sand it, scrape it, shape it, or even interface it (adding layers) of gesso on gesso.
Any imperfections can be dealt with in this 2nd stage. But in the end, the object is to get a gesso that has a smooth as glass surface with the LEAST amount of imperfections on the face of that gesso..
That is achieved by using a lipstick shaped AGATE burnisher and polishing the gesso. Once the polishing process begins, the gesso will after direct contact with the burnisher, take on a gloss appearance. It goes from MATT TO GLOSS. This polishing process was quite time consuming by the gilders of that medieval period. Any minor nicks or imperfections were actually polished out. That gesso looked like a sheet of glass. That was the FINAL object before moving into the 3rd and final stage. The gilding process.