Framing Antique Maps
Antique maps, as with other rare and antique paper items, require proper conservation framing to ensure longevity and its protection. Unless trained to correctly frame a map, some framers use over the counter tapes, glues or other adhesives for mounting. It is highly recommended to use Mylar or other non evasive hinging methods to protect from tearing, staining, and eventually removal.
Another common framing method in routine framing establishments (including arts and craft chain stores) is the use of any foam core board as backing. Foam core is a very common material used in the framing industry for backing the artwork. So, in most cases, the framer mounts the artwork directly onto the foam backing board. Tests have shown that this common technique is very harmful to artwork and even effects it over time through out-gassing.
Out-gassing is the release of contaminated gasses from the object of origin to the environment. Maps like any other antique or fragile paper item is very sensitive to any such contact and can deteriorate the map over time.
This is an example of "acid free" foam core after being in frames for about 10 to 15 years each:
This is an example of so called "acid free" foamcore. Notice the stark yellowing from outgassing.
Brittle "acid free" foam core that has been out-gassing
Although most framers only offer foam core products, make sure you ask the framer that you want both museum grade 100% cotton rag backing AND archival coroplast for final backing. 100% Museum grade cotton rag matting is the only material that is truly labeled as "Museum Level" and it's what museums and trained conservators use for matting and framing. For final backing, Archival grade coroplast is strongly recommended and it won't out gas nor deteriorate.
Nothing should ever be compromised regarding the framing of your important rare map collection. Many antique maps have original and older coloring which can be greatly compromised with the wrong framing materials. Even recent coloring can be greatly affected over time. After all, preservation should be part of the framing package. Doing otherwise will create problems down the line.
When inquiring about glass, only use 99% UV filtered glass. Don't use a substitute! I hate to say it, but have the framer reassure you that he carries and uses this material. There are many manufacturers and suppliers who sell a lower grade of glass at a much cheaper cost to framers to save them money and increase their profits. But, it is bad on your antique map collection.
1676 Speed Map of Maryland and Virginia
Imagine light hitting you framed maps every day. Imagine using the wrong grade of glazing and how that will compromise your collection over time. Fading and discoloring is something that is so subtle that you may not notice the effects. But, over time you will notice a difference that will shock you.
Over the years, I have taken apart frames for customers who realized that some of their artwork showed signs of such deterioration. Coloring on antiques maps is very sensitive to light and any intense light without protection will cause changes over time.
Have you have seen verdigris change color or eat through map paper material over time? That is because the framed map was hung in direct light over time. Of course, it can also be from improper storage as well. But, in either case, use proper measures to ensure its protection.
Remember, your artwork is in constant contact with light daily. Even if you use the proper glazing, you still need to keep your artwork out of DIRECT sunlight. Using inferior glazing and the light cause rapid deterioration.
As mentioned above, a key ingredient to proper museum quality framing is the application of museum grade 100% rag matting. Don't accept other mat types. Even if the framer tells you it's "acid free", I can almost guarantee you it's not unless they show you it's made from 100% cotton material. Other "acid free" mat boards, will leave a darkened ring around the antique map, which is called a "mat burn". These mats are made with wood pulp and chemically treated.
If you have ever purchased previously framed antique map in older or not properly treated framing jobs, you will notice a mat burn around the artwork. And that was due to acidic mats mounted onto artwork. This was and is a common practice in the framing industry.
Protecting your antique maps and ensuring proper framing is done to them is very important to their protection and longevity. If you want to preserve your maps and enjoy their beauty on your walls, make sure the frame contains the correct materials.