It so happens that I had a charcoal drawing waiting to be framed and I chose a Graphite color metal frame and an off white mat with acrylic glazing. Most of the frames on their website both wood and metal are narrow between 1 and 2 inches so these frames are best suited for works that will be matted. I don't think they would take stretched canvas well.
The frame itself is very sturdy, Nielson brand and I loved the finish and color, which I worried would be too light but it was just perfect. I had a bit of difficulty assembling the frame when one of the corner pieces simply wouldn't slide into the track on the frame piece. I tried every which way to no avail. Peter at PictureFrame Guys says that has never happened before, but promptly sent me another side piece and the frame went together easily in just a few minutes. My feeling is that this was just a one time glitch and should be of no concern.
My drawing was 8x10 and I loved the size and proportions of the mat, 73/4 X 93/4. A few weeks prior I had framed another 8x10 charcoal drawing with a frame and mat kit I bought at the art store and the mat was quite a bit narrower so when I looked at them side by side the Frame and mat from http://www.pictureframeguys.com/ gave the drawing more room to breathe and gave me a larger more substantial work overall.
The mat is Crescent Select, a pulp-based product that is chemically treated to eliminate the acidity. Peter from www.PictureFrameGuys.com assures me it should be fine for at least 15 years (but more like 20+) and there should be no acid bleeding or other degradation of the artwork. Same for the mounting board. It is not entirely acid-free, but also a chemically treated board that reduces / eliminates acidity. Both are a very high standard in quality framing, if not conservation-grade. I am kind of a stickler for using really good quality conservation grade materials to mat and frame work, and www.PictureframeGuys.com does indeed carry a line of conservation grade materials which are more expensive naturally. But, they are the same level of conservation material that is used by the Library of Congress, a plus if you need or want to have conservation grade framing materials. So let your budget and your work be your guide. If you have a piece that's really your best, or you're supplying a high end gallery with work, submitting to a musuem show etc. I'd recommend going conservation grade. Otherwise, their normal grade mats and backing board should be fine.
The plexi-glass was a bit of a challenge but only because I was framing a charcoal drawing, though you might find this with pastel also. The static charge fo the plexi kept pulling charcoal dust onto it and I had to keep removing the plexi and cleaning it before I got really good at gently placing the artwork into the frame and beneath the plexi. if you're framing a watercolor, photograph, colored pencil, collage or graphite drawing you would have absolutely no problem. But that prompted me to ask Peter if they had an option for glass or if you could buy the mat and frame kits without glass, so you could buy your own. The answer is yes, http://www.pictureframeguys.com/ is working on offering glass but right now they are still working on finding the best ways to pack and ship it, and they do offer frames and mats without the acrylic glazing if you should need that.
If you visit thier website you will see a good variety of frames to choose from, framing accessories, framing basics and tips, all very helpful. So if you're in need of picture frames you now know where to go. For selection, quality of product and good customer service I give http://www.pictureframeguys.com/ 4 stars!