If you plan to start soon after you purchased your paint, you may only need to stir the paint lightly before you use it.

For a single can, pour off the thin paint at the top of the can. Stir the thick paint at the bottom, then pour the thin paint back in and stir.

If you have several cans, the pain in them could vary slightly in color, especially if it was custom-mixed. To get a uniform color throughout your ‘job, box the paint. Some paints may also require gaming or thinning.

Boxing Your Paint

Pour all the paint for the job into a 5-gallon pail or bucket. Stir until it is thoroughly mixed and uniform in color. Boxing eliminates slight color variations among cans of paint. Drive small nail holes into the grooves in the can rims, then pour the boxed paint back in the cans. Trapped paint will drain through the holes in the can. Tightly seal the lids on all but the first can.

Straining the Paint

If the paint is separated, stir the thick paint up from the bottom of each can until it is as free of much lumps as possible. Then, box as described, pouring it into a cloth paint strainer into the pail. If the paint has thick scum or skin, don’t try mixing it back into the paint. Instead, remove the skin and set it aside.

When it has dried, wrap it in a newspaper and discard it. Box the paint as described, pouring through s cloth paint strainer into the pail.

Thinning the Paint

If the paint has been stored for some time, it may need to be thinned as well as stirred. Box the paint and, as you stir it, decide how much thinning, if any, the paint needs.

To determine how much thinning your paint needs, make several test strokes with the boxed paint. If your brush furrows or your roller nap pulls the paint away from the wall, it needs thinning. Add an ounce of water or paint thinner, as appropriate; stir thoroughly; and test again. Continue this process until the paint makes an even film on the wall.

Don’t over-thin. If you have thinned and the paint still does not flow or adhere properly, talk to your paint dealer. You may be using the wrong brush or roller cover, or your surface may not be clean.