Size gilding is perfect when applying precious metal or imitation leaf on surfaces that are neither too undulated nor porous. Since it does not require complex preliminary preparation steps, this is a relatively simple technique that is significantly less laborious than water gilding. The name of the technique comes from the adhesive, or size, that is used to make the leaf adhere to the surface you are gilding. The type and composition of the adhesives vary according to the material on which the leaf needs to be applied. We will therefore talk about water-based size gilding, alcohol-based (solvent) size gilding and oil-based size gilding. Each one will require different gilding times. Using size does not normally have a burnishing phase, therefore – once gilding is complete – the leaf will be less shiny compared to an application with the water technique. It is also advisable to always protect the leaf that is applied with size gilding, in order to guarantee greater resistance over time. The type of protection you use will vary depending on the material you are gilding (wood, plastic, glass, metal, etc.), the environment in which the gilding is carried out (internal or external) and the metal (precious metal or imitation leaf).
Water-based size is particularly suitable for surfaces with medium porosity, such as wood, plaster, stucco and paper.
The alcohol-based size is perfect for smooth and compact surfaces such as metal, plastic and glass. Both are suitable for interior gilding.
The oil-based size gilding is the ideal solution when gilding objects that will be outdoors and it is suitable for both compact surfaces (such as glass or metal) and more porous surfaces (such as wood or stone).
For outdoor gilding we recommend that you always use the size gilding technique and exclusively pure gold leaf.