A.J. (Hudderslield) asks: "How long must one allow a painting to dry before varnishing it ?" - That depends on circumstances. For a lightly laid in picture, twenty-four hours is usually sufficient; for a very heavily impasted one, allow not less than four days, and, if possible, a week. This is supposing that no dryers are used in the painting. All dryers are to be avoided, if possible, as the best of them produce an unnatural action of the pigments in drying. No raw picture should be varnished. A little French retouching varnish will bring the dead colour out sufficiently. When the picture is a year old it may be permanently varnished; if you can make up your mind to wait two years to give it its dress suit, it will be all the better for the picture.