atapaz, I'm glad to hear you say use archival only mats. this is so important. There are several mat companies out there and they will all claim to have acid free mats. But, they are not all created equal. I use primarily Bainbridge and Cresent mat companies and both companies have a regular mat line and a conservation / rag mat line. Choose conservation and 100% cotton rag mats. The regular mat lines have only a paper shield that touches the art work that is acid free. The rest of the board is not acid free, and acid will migrate. Conservation and 100% rag mats are acid free through and through. Above all do not
use cardboard behind your artwork. This is the biggest mistake that is made. Use another piece of acid free mat board or acid free foam core. Okay, off that soap box.
This is gonna go long folks.
There are many shades of whites and many colors available. Your whites can be cool or warm, lean to yellows, blues, greys, ect. Your choice should be influeced by the white of your paper (speaking of watercolor) or the lightest value in your art, (speaking of other supports). The free specifer chips that you can get limit you to correctly choose the proper mats. It is best to hold a corner sample over the piece to choose the correct white. If you cannot afford to purchase a set of corner samples to choose your colors by then shop for a framer who you can trust to give you the conservation framing you need and who has a good eye for complimenting your art with mat selections.
I am a professional framer and as a framer it is up to me to determine my customers needs. Are they artists who will be entering thier work in competions or in a gallery to sell? If so, I lean to the white top mat, and one or two colors and values for the under mats to accent the art. But this is not a hard and fast rule.
If my customer is wanting to match to thier decor, I try to bring a balance to doing that without sacrificing enhancing the art work. I am more likely to use special ehancements to the matting choices and style in this area. Enhancing the art or print is the most important thing.
I firmly believe and have proven over and over again that a beautiful work of art can be brought down with the wrong choices and a mediochre can become truly special with the right choices.
I tend to use fabric mats with fillets on my own works. I feel this high end matting choice brings warrented richness to an original work of art.
Framing is expensive and all artist face this and tend to short cut thier work with the framing because of it. But do not short cut where conservation is concerned or by choosing ready made colored mats. As an artist you know "not all blues work together". Your art work deserves better. If you have made the chose of using professional pigments, papers, and products why would you chose anything less in the presentation of it?