Glycerine is used in wood finishing in the manufacture of water-based dye and alcohol varnishes.
A tip to facilitate the application of a varnish with shellac is to add about 60 ml per liter of glycerine. This will increase drying time and avoid overlap during application.
Pure Glycerine is used in the water-based dye fabrication. Like stains based : walnut stain, annatto seed, mahogany and stain of milk and others. Add about 10% to 25% of glycerine to the mixture. This will prevent the grain of wood to lift during application and facilitate the dispersion of pigments.