Bell Foundry style
This style of vent cover is hand cast. As a result the faceplates are about 1/4 inch thick and quite substantial looking. They are available in a great many standard sizes, and custom sizes can be made although there is a cost for creating a mold.
These are cast in either bronze or aluminum. Aluminum castings are painted either black, brown, or paint ready white. Bronze has three patinas to choose from as well as one plated finish, which is a brushed nickel.
You get your choice of either a damper, a screen, or neither. Screwholes and matching screws are available at no additional cost. The screen is a good idea for a cold air return since it will help prevent looking inside the duct. It is a flat black and blends right in. It forms a box and helps position it in the opening. Flat screening is available upon request. There is no charge for screening and you can remove it with a screwdriver if you decide you don't want it. However, if your air return is on the floor it does a good job of catching anything you might drop in the opening!