Graining grounds which are mixed with all oil are very liable to crack and check after varnish has been applied over them. Care should always be used in noting that the undercoats are thoroughly hard before applying subsequent coats. There should not be too much oil used.

If the priming is to be applied to the bare wood, reduce with half oil and half turpentine. Allow this to thoroughly harden through, putty, sandpaper smooth and apply a coat of paint, mixed flat, to which has been added a half-pint of hard-drying varnish to the gallon of paint. When hard, rub smooth with fine sandpaper or steel wool and apply a coat of the same paint with the addition of varnish to allow of drying with a slight gloss, or a small amount of oil can be used, but not enough to cause the paint to dry tacky. If the surface has been sized, the first coat should be mixed with 2-3 turpentine and 1-3 oil, smoothed off and finished with one coat as recommended for finishing on bare wood. Graining color can be worked over this ground without danger of cutting through with the graining combs or when cutting out growths, as is often the case when oil is used in ground work.

It is best to grain in distemper for interior work. For exterior work, more oil can be used for building up the ground work than for interior. However, if the work is to be varnished, most of the oil should be cut out. A great many painters prefer not to varnish exterior work, but apply a coat of oil, rub off with a soft cloth and let the work remain with this finish. Where varnished work is used on the exterior, the graining- should be done in distemper if possible, or the oil graining color should be allowed to stand until thoroughly hard before applying the varnish; this insures against blistering and cracking.