Traditional water gilding requires precise timing. The size must be at exactly the right moisture level when the leaf is applied. Too soon and it is too wet. Too late and it is too dry. This narrow window demands skill and experience. The Kölner system addresses this problem.
The Kölner system uses a specific synthetic size (typically Permacoll or similar products) that maintains an open application window much longer than traditional size. This means you have more time to apply the leaf without rushing. The adhesion quality remains high. The technique becomes more forgiving.
The system does not replace traditional technique—it supplements it. For gilders working at scale, or for applications where traditional timing is impractical, the Kölner system is a practical solution. It maintains the quality of water gilding while removing one of the major technical hurdles. For fine art and precious surfaces, traditional water gilding remains the standard, but the Kölner system has a real place in contemporary practice.