Charbonnel Gold Size...New - Lead Free Formulation. Gold size is used to adhere gold leaf to a surface. Generally artists will simply apply the leaf to their wet paint foregoing the use of size. Although this may work to hold the gold in place results are mixed. Charbonell Gold Size is specifically formulated to correctly adhere leaf for optimum brilliance and lustre. When you consider the cost of the actual leaf it really makes sense to spend a little extra to achieve the best metallic finish possible. We offer two types of gold size a 3 Hour and a 12 Hour Size.The 3 Hour Size means that after application the size will be be ready for gilding in about 3 hours. This works best for gilding small objects or small areas since the open time is relatively short. This size is often referred to as Quick Size.12 Hour Size is ready for gilding in approximately 12 Hours after application. This is ideal for gilding large areas because the open time allows you more time to finish the area to provide a more consistent appearance to the gilded surface. This size is also referred to as Slow Size.