Part of each child's education, whether homeschooled or not, should be exposure to the best artists and the best works of art. Art books are usually quite expensive, although they can sometimes be found on sale, but even then you are possibly bringing into your home art that you do not aprove of or consider appropriate for your children. Here's my frugal solution:
Next you need calendars. Lots of calendars. We bought each of the above for $1 each at a local bookstore. Watch closely around the end of January because they get drastically marked down. You may even be able to find some on Freecycle or by asking relatives. I always save our calendars so we had plenty of options.
Pull the pictures out of their binding (they are usually only secured by 2 staples). Write the desired information on the back, if you wish (artist, time period, title, etc) or make an index and list each work of art in your book. Insert the art page into the page protector. I use the 12x12 post bound because the page protectors open at the top, making insertion quick and easy. The above album holds 20 pictures. You can also buy extra pages for this type of album.
Here's one spread inside our album:
Each calendar has at least 12 works of art -of course! - and many often have 1-2 extra. So, if you pay $1 for a calendar each sheet is $ .08 or less. We're already starting another album and adding refills to our first. We hope to eventually have books dedicated to our favorite artists and books for specific periods. We do buy good art books when we find them but our homemade one is our favorite so far.
Check out Biblical Womanhood for lots of great frugal hints, tips, and ideas.