Gilding on Glass

How to gild on glass surfaces. - 'Reverse Gilding on Glass' and 'Verre Eglomise'

Applying gold leaf to glass is a technique that has been employed for centuries by sign makers, lettering specialists, and specialty mirror makers. Glass gilding is also know as 'Reverse Gilding on Glass' and 'Verre Eglomise'.

Glass gilding employs a specific type of adhesive glue know as Gelatin Size. This is dissolved in warm water and floated over the glass surface. While still wet or pooling, the gold is immediately applied. Once dry there is no discolorization when viewing the gold through the glass (and adhesive layer). There are a number of speciatly brushes used specifically for applying gelatin size glue to glass - many of which are described below.

Gold, Silver and metal leaf can all be used in gilding on glass. When using Genuine Gold leaf we offer a higher quality gold leaf know as Glass Gold. This term applies to gold leaf which is selected for it's higher quality - having fewer pinholes and irregularities, making it ideally suited for reverse gilding on glass.

Application Technique

Cleaning the glass surface

First, insure the glass surface is completely clean. Generally Denatured Alcohol works best as a cleaning agent. Be sure to use a lint free cloth.

Mixing the gelatin size

Size refers to the adhesive used to adhere the leaf to a surface. There are different kinds of size adhesive dependant on the finished look you desire. Generally, we use Gelatin Glue size for Glass Gilding.

Mixing ratios. Platinum white gelatin sheets are the alternate to 00 gelatin capsules. Each sheet is embossed with 80 diamonds.

Genuine Gold, Silver, Platinum and Palladium leaf. A two diamond section is equal to one 00 gelatin capsule and, when placed in one half pint of distilled warm water, it will make an average strength batch of gelatin glue size.

Imitation Gold, Imitation Silver and Copper leaf. A four diamond section is equal to two 00 gelatin capsule and, when placed in one half pint of distilled warm water, it will make an average strength batch of gelatin glue size for metal leaf.

Applying the Gelatin size adhesive

Apply Gelatin sizing (adhesive) to the glass surface where you would like the gold to adhere. There are a few specialty brushes designed for this application process that will facilitate the gelatin application, see below.

Applying the Leaf

Apply Genuine Gold or Silver leaf - surface or loose leaf (note: Patent Leaf will not work for gilding on glass). You can use 22kt or higher, depending on final look and color tone desired. View our Gold Leaf Color charts for more details on specific gold types and color tones of our different alloy blend.

The leaf must be applied while the surface is still wet with the gelatin size. You will apply a liberal amount of size, flooding the surface, then using a Gilder's Tip Brush, quickly and carefully move an individual sheet of leaf directly onto the wet surface. It will tend to 'jump' to the surface as you bring the leaf close. When working on a verticle surface, the liquid will be flowing downward quickly, so you may need a soft mop brush to 'hold' the leaf in position. When ready to move on to the next leaf, apply more gilders liquid as needed and repeat as before.

Allow gelatin size to dry

Allow Gelatin Sizing to dry fully then remove any excess leaf bits with a soft Squirrel Mop brush.

'Back-Up' the gilt surface

Back-up the gold with 'Gilder's Back-up Paint' or 'Gilder's Back-up Varnish'. Often Gold Lettering and graphics are painted over to protect and seal the gold as well as increase the reflectivity and luster of the gold, as seen through the front of the glass or mirror. This color can affect the Gold tone slightly. Using a Terracotta Red will warm the Gold, while using a Black can make it appear bolder and colder. Yellow tends to mellow the Gold and add depth. Alternatively, you can skip the paint layer and back-up the letter forms or graphics directly with clear back-up varnish, see step 6. If you choose to use paint, be sure to add a final layer of clear varnish over the painted surface.