The purpose of using a primer is usually to help create a tight bond between the paint and the surface to be painted. Here is a list of situations that would be good causes for a primer:

• New wood or plaster
• Repaint jobs when the surface is uneven or badly deteriorated
• Repaint jobs when the surface has been stripped or worn down to its original substrate
• Bare cedar or redwood with tannin stain problems
• Surfaces with stains or grafitti Bare sheetrock, plaster, masonry, brick
• Slick surfaces like tile and high gloss enamels
• Iron and steel that need protection against rusting

To calculate the amount of paint needed for a job, first determine the number of square feet of surface to be painted. Multiply the length of each wall by its height and add these figures together to determine the amount of wall surface area. Multiply the length of the room by its width to determine the surface area of the ceiling. Divide surface area by the spreading rate (coverage rate) of a gallon of paint. The result will be the approximate number of gallons needed. Spreading rates are usually included on the directions panel.

When properly stored, leftover paint can last for years. Cover the opening of the paint can with plastic wrap and replace the lid. Make sure the lid fits securely, then store the paint can upside down. This creates a tight seal around the lid, keeping the paint fresh for touch-ups and other future projects.

Skimping or spreading paint too thinly causes uneven oil absorption, resulting in loss of gloss and eventual color change. Poor quality paint will also spot. Spotting is also caused by moisture condensing before paint dries, common when painting in the fall and late afternoon, when dew or condensation form. Paint only when air, surface and paint temperatures are at least 5°F (3°C) above dew point. Avoid painting when rain threatens.

Paints are being made heavier in body. The resulting thickening of consistency requires the use of a stiffer brush. By tapering, the bristles on either side of the brush are brought together and made to support each other. This not only provides greater strength but also makes the bristle as a whole more elastic and easier to work with. The second main reason for tapering is that it preserves the active life of the brush. There is a tendency for particles of dry paint to deposit around the bristle, just below the ferrule. Without tapered construction these paint particles would eventually spread the bristle in every direction, causing it to fan or finger.

Lambswool is a natural material preferred by many professional painters because of its ability to carry large amounts of paint per dip. Lambswool covers can be used with alkyd or solvent thinned paints. Lambswool is not recommended for water base paint, because the alkali in latex paints neutralizes the wool's tanning acid and actually detans the leather, making it susceptible to rotting.

For the most realistic softwood grain effects, use a Graining Rocker to create authentic heartgrain strips randomly between strips of straight grain. Press the face of the Rocker into the wet glaze and pull it along with a smooth action, slowly and continuously rotating it back and forth in a rocking motion. As the tool is rocked, the character of the grain changes dramatically, producing heart grain figuring.