The framing industry has no books, no set theory, not hard and fast rules on how to pick colours. There are some personal opinions from various writers but that's all they are. However it is not as hard as you may think.
The obvious starting point is to go for a colour that's in the picture, then vary the shades from darket to lighter to see which suits best.
An Inner mat is the smaller window just surrounding your art work and it is usually used to sharpen the image. Darker inner mat will increase the contrast between the light and dark areas of the picture, making the image easier to see. Therefore, adding an inner mat is both decorative and functional.
An outer mat is a bigger window closest to the glass, and sitting just on top of the inner mat. There is one or two rules I can give you for choosing the outer mat. Always make the outer mat border at least 2 1/2" (60mm). 2" mats do not work. The wider the mat the more you see the picture. The other rule relates to the surroundings. The colour of the outer mat you choose should have NOTHING to do with your taste or the colours in the room. If you do your job correctly you should see the picture, not what surrounds it. Many people make mistake by starting to use their personal taste or decorator themes in framing.
You can practice choosing the right mat board colours using the Smart Framer program on our web site. Upload some of your own digital photos and frame them.
With more than 30 years of experience in the business of picture framing, Gary Leete is the owner of Melbourne-based FrameCo Picture Framing Supplies, a company that specializes in DIY framing tools, start up kits and framing accessories. For further information on FrameCo products and services, feel free to email firstname.lastname@example.org