Sending your book to be bound is definitely a sign you've accomplished something big, be it a self-published fiction book or a report in book form for your employer. When you arrange for binding, you'll be able to specify the materials and colours used for the final product. One option will be to use archival materials such as acid-free and neutral-pH paper and boards. If you want your book to continue looking physically good for years, definitely use the archival materials for bookbinding and printing.
What Do Archival Materials Do?
The wood pulp used for paper contains compounds that deteriorate over time. When they deteriorate, they make the paper — already somewhat acidic by nature — even more acidic. This isn't an acid that can harm you, but it's one that can make paper products turn yellow and become so brittle that they crumble. Have you ever picked up an old paperback book to find the corners sort of disintegrating? That's the result of acidic paper. To avoid that problem and have books that look good for years, you want to use paper products that are not acidic. That includes materials like the boards used for the front and back covers of a hardback book.
There's one more benefit to using non-acidic/acid-free materials, and that's the protection of adjacent materials. The acidic nature of the paper won't make it start leaking acid, but anything touching the paper or board can be affected by the acid and start to suffer itself. This is why acid-free materials are so big in the scrapbooking world; otherwise, photos and other keepsakes can themselves turn yellowish and brittle.
Why Print And Bind Your Book With Archival Materials?
If you hope that your book is around for a very long time, then you'll want to use archival, acid-free materials. But if your book won't be around for long, such as an operational manual for equipment that's going to be upgraded in a couple of years, preservation might not seem that important. However, the chances that there will still be people using the old version of the equipment past that time (or whatever the book describes) means that the book may yet stay on shelves for a while. It's better to use archival materials for the printing and binding to begin with.
While archival materials can cost more, they generally don't cost that much more. You should be able to find economical options for your book if you're working with a tight budget.