Most of the posters I sell here on my website are archival linen backed. Why do I do this? Because most of them are old and exhibit signs of aging such as brittleness or tearing. Because posters were made of fragile paper, almost all have been damaged and existing damage and flaws will likely to worsen over time, especially if disregarded or frequently handled. Linen backing is the best way to preserve and stabilize your poster and provides a canvas for further restorative work (which we will talk about later).
Linen backing a poster on canvas requires three elements. Linen, acid-free lining paper and a Wheat starch solution containing an alkali buffer which when all combined together produces a stable - but reversible - acid free environment for mounting a poster.
While a minority of (mostly) European-based poster collectors decry the linen backing process, believing a poster is no longer original or more difficult to authenticate, the vast majority of collectors world-wide believe the linen backing process to be an effective preservation and stabilization technique. When done professionally, the result is museum quality and fully reversible.
When it comes time to sell a vintage poster, there is usually no difference in value between those that are linen backed and those that are not.