This is a technical grade of fine-mesh granular gelatin, meaning the lightest and most transparent grade, that is can be used as an alternative to rabbit skin glue when gilding.
Traditionally hide glues (such as rabbit skin glue) have been used in the water gilding process, either mixed with whiting to form gesso or mixed with gilder's clay to form a bole. Concentrated Size can be used in the same way as hide glues and for many of the same applications, including use in bole and gesso.
To prepare the gelatin for use it first must be soaked in water overnight in a mixture of 1:10 parts glue to water (note: this is our recommendation, although ratios may vary according to your own needs), pouring away the excess after the gelatin swollen and absorbed the water. Before working the gelatin must be melted by immersing it in a sealed container into a warm water bath.
An alternative method of use as given to use by one of customers is to mix 1 part glue to 10 parts water by volume. Allow the gelatin to soak until it is swollen with the water, this should happen within one and half hours. There should be no excess water to pour away. Heat the swollen gelatin in a microwave on a low heat for about 10 minutes or until it is fully dissolved, then use.
