Try putting your artwork behind several different mats. This can be done at most photo stores, or use the corner samples at a custom cutting counter. It becomes readily apparent that the perception of the image changes radically with different combinations of colors. Most will enhance the image, and some will stand out immediately as excellent choices. In most cases double mats will work best, but images without bright colors will often work best with a single mat. Adding a single or double mat will usually be cost efficient, since most end-users will appreciate the added value. Here are some fundamental ideas when considering using art mats.
Single mats: If a single mat is used, it is often safest and most desirable to use a neutral color, such as off white, cream, light grays etc. These go very well with most images and fit into most home settings. If you wish a stronger color, try to match the mat color with a dominant color in the image. i.e. Lots of dark green trees in the picture, use a dark green mat. For black and white photographs, off-white mats with a black core are very effective.
Using a double mat: Double mats add considerably to the richness of the presentation. The safest method is to use a neutral outer mat, and a color for the inner mat that matches a dominant color in the image. The amount of the inner mat that can be seen is called the “reveal”, and varies with the size of the mat. A reveal of 3/16" is close to being an industry standard, but use your own judgment.