Colors and gilt on glass
You should not put as strong gummed water on glass for the silver layer as for the gold layer because a silver leaf is twice as strong as gold leaf. Also, silver is harder and therefore does not scratch as easily. And if gum was not a little [too] strong for silver, it would not crack so clearly. When you work, the exhalation of your breath humidifies the leaf lying on the glass, and therefore it would be good, when working, to heat it up a few times. You have to very thoroughly wash what you want to be empty and used as a surface painted with colors, because if it is not really clean of the gum’s grease and viscosity, and of other things, the colors will not be so clear on it. To advance your work you can smooth with a pumice stone, or [you can do this] to better lay down gum and leaf on a cut paper. This way, you will have to do very little repairs. If you want a gold color there without gold, mix soaked dried saffron with a little bit of massicot.