This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
Before the first coat is applied to wood, all holes should be filled up. The filling usually employed is ordinary putty; this, however, sometimes consists of whiting ground up with oil foots of a non-drying character, and when the films of paint are dry, the oil from the putty exudes to the surface, causing a stain. The best filling for ordinary purposes is whiting ground to a paste with boiled linseed-oil. For finer work, and for filling cracks, red-lead mixed with the same vehicle may be employed. For porous hard woods, use boiled oil and corn starch stirred into a very thick paste; add a little japan, and reduce with turpentine. Add no colour for light ash; for dark ash and chestnut, use a little raw sienna; for walnut, burnt umber and a slight amount of Venetian red; for bay wood, burnt sienna. In no case use more colour than is required to overcome the white appearance of the starch, unless you wish to stain the wood. This filler is worked with brush and rags in the usual manner. Let it dry 4S hours, or until it is in condition to rub down with No. 0 sandpaper, without much gumming up; and if an extra fine finish is desired, fill again with the same materials, using less oil, but more japan and turpentine. The second coat will not shrink, being supported by the first.