Safe method for mounting vintage flag?

I have an 1800s US flag that I would like to make a simple shadowbox frame for. I plan on using acid free foam core wrapped in cotton muslin or other archival fabric and then mount the flag to that.

Is there a safe, non-damaging method to mounting a cotton/wool flag to a fabric backing? I've seen some people use pins or sew directly to the backing but I'd really like to not put any holes in the flag.

Is there a double sided tape that could work? Any other ideas?
Thanks!

 

https://spicerart.com/treatments/large-textile-mounts/

 

How large is the flag? Do you know what fibers it is made of?

I would recommend avoiding any type of adhesive or tape. The ageing properties of many adhesives can be unpredictable, and they can be more difficult to reverse in the future.

A "pressure mount", as described in the link Kronos provided, might be a solution for a smallish flag. It becomes more difficult to maintain even pressure over a large area. The effectiveness of a pressure mount may be assisted with some stitching. There is also the option of incorporating a "friction" component by covering the padded backing board with a (archival quality) napped fabric with some "tooth" such as a velvet or flannel, which helps to keep the textile from shifting.

There are risks to encasing the textile in direct contact with glass or plexiglas, if fluctuations in relative humidity may occur. One of the primary reasons for using window mats on framed prints is to provide safe breathing space between the artwork and the glass, and the same concerns apply to framing textiles.

If the textile is in good condition and not fragile, stitching may be the safest option. It is a known technique, and easily reversible if necessary. Textile conservators are experienced in inserting their stitches between the threads of the original textile (sometimes under magnification), to avoid creating any new holes.

 

Thanks so much! That makes sense
It's a bit of an odd size, roughly 24x48".

I was hesitant of a pressure mount due to humidity as well.
Is there a way to minimize the possible humidity issues with this method?

I like the idea of a friction type mount, might think on that a bit.

I was wondering if there was an in between. What about having small pieces or a strip of acrylic or even foam core, etc. around the edges of the flags that apply pressure to the backing similar to a mat? I do not want the mat look so I'd probably have to get creative.

My main concern is storing the flag archivally while being able to still view it. I don't care as much about how it looks necessarily (meaning, it doesn't have to be a "pretty" frame job)

Stitching a one of a kind piece seems daunting to me. I just don't know if I can feel good about putting holes in it, even if they are small

 

Friction mounts are sometimes used with minimal, or no stitching, if the support can be placed at an angle - the greater the angle, the less likely the textile will slide down.