Each page in the library bound mat album has two components: rigid bound-in pages, which look like frames and flexible cardstock mats, with die-cut openings for your photos. You need both in order to complete the album.
The rigid bound-in page is sort of a frame to hold the mat. You can choose an album to hold 24, 30, or 36 mats.
The flexible mat, which holds your photos, slips into the rigid page. You'll want to make sure you order the correct number of mats for the album you have chosen. You can select mats to hold a variety of print sizes from 2" x 3" up to 10" x 10"
The flexible mat is a sheet of cardstock with die-cut window openings to frame your photographs. The front is the only part you see once the album is assembled. The back of the mat has a protective sheet of white paper which you flip back to mount photographs.
Place your photo face down, so the part you want to show is centered over the die cut window opening, and then using photo safe tape, tape it down so it is fixed in position. Once you have all the photos for the mat affixed, you can flip the paper backing sheet down. If you like, you can secure the backing sheet with a small piece of tape.
The rigid page is two-sided, so you will slide two mats in--facing back to back.
At the top of each page is a slit. Gently pull the slit open and slide your mats in.
Repeat the same steps until every page has been filled.
The album is designed so there is no bulge when all of the mats are in place. Every page lies nice and flat when the album is open, and the album closes perfectly flat when it is closed.