This size is an absolutely fantastic size (adhesive) used for applying metal leaf to a variety of sealed surfaces.
 
It is one of the easiest sizes I have ever used as it gives you a really long working time with a short waiting time. The sizes takes approximately 15 minutes to reach tack, after which is remains 'tacky' for 24 hours - plenty of time to apply your metal leaf!
 
It can be thinned down with water in order to prevent brush strokes being visible under the leaf, but make sure the pieces is WELL SEALED before application - especially if thinned!