A spray varnish, such as Golden Archival Spray Varnish is a good alternative to using a brush-on varnish. Spray sealants protect the artwork just as well from environmental damage, such as dirt, dust, smudges and UV rays. They can also protect your painting against damage from moisture.

Some artists prefer using a spray sealant to varnish their artwork, because it allows them a smoother finish than they could achieve when brushing on their varnish. When you spray varnish your art, you don't run the risk of the brushstrokes showing up in your layer of varnish.

On the other hand, there are a few things you need to be careful of if you use a spray varnish. First, make sure you spray varnish your painting in an area that has adequate ventilation. The best place to spray varnish your painting is outdoors, preferably when it is not humid.

Carefully follow the directions on the can. Spray lightly, moving back and forth in a steady sweeping motion. You don't want to concentrate too long on one area or you risk overdoing it.

Whatever spray varnish you choose, make sure it is removable, which is useful in case something sticks to the varnish before it has dried, but also equally important for conservation purposes. Also make sure your spray varnish is labeled "non-yellowing", otherwise it may turn your painting yellow after a few years.

Two brands of spray varnish that I highly recommend are Golden Archival Spray Varnish and Lascaux UV Protect. These top-quality spray sealants are available in gloss, satin and matte finishes.