Consolidation is one of the most basic and least understood processes in conservation and restoration. Fifty years of conservation science has focused on the chemical stability of the consolidants, but has provided very little understanding of the treatment process itself, or the optics and mechanics of the results. When one applies consolidant solution to a painting or a sculpture or a pastel, one hopes that capillarity will carry the solution into all the necessary places, that after drying the consolidant will have remained in the necessary places, that the object will be sufficiently strong, and that the appearance will be acceptable. All too often, unfortunately, one seed failure of some or all of these objectives. I believe that much of what the experienced practitioner manipulates consciously and unconsciously to achieve good results can be understood through a physical model of the process. I think I have also come to understand the reasons for the special magic of traditional animal glues (gelatin) in consolidation treatments. A few parts of this model have been published earlier but most have not. Practical summaries: The reader looking for practical suggestions can skim through the article and read only these bullets.