[when] do you need to worry about archival materials?
When you’re shopping for bookmaking materials you’ll run into a lot of indicators of how archival a material is - i.e. how well it will hold up over time. As paper, glue, board, and cloth age, some materials are more likely to break down, warp, or fall apart. For example, acid-free paper and board are more archival than their more acidic counterparts (those with a pH level at or under 7.0) because acidic materials will gradually yellow and become brittle. As is true with most things in this world, some elements of book aging are simply unavoidable, but there are some simple material considerations you can make that will help keep your books intact for a long time.
It’s my opinion that using acid-free materials is a good rule of thumb for creating archival books for personal use. Beyond that, the ‘best’ materials to use to create books vary by project - while some materials may be more archival in their strength and durability, sometimes you’ll need a thinner or more flexible material to achieve the proportions you’re aiming for. Some super-archival materials can be cost prohibitive and require heavier-duty tools, and sometimes they’re simply not necessary for what you’re working on.
Standards for archival-ness in bookbinding are often very high, and for great reasons! We want bound books in libraries to hold up to rigorous use over decades, and it’s wonderful that so many incredible ancient books have remained well preserved. Whether or not those rigorous standards should apply to what you make is entirely up to you.
For more material info, check out our love letters to PVA and bookcloth.