I'm excited at how this project turned out.   It cost me all of about $4 to do.  The frames are from the dollar store that I painted white.  The baseballs are vinyls that I cut out on my Cricut and the mats in the frames are made from poster board and fabric scraps.  Warning I took a lot of pictures on how I made the mats.
I used the paper that came in the frame as my guide as to how big to cut the poster board.  I then traced around it.
I cut it out then repeated the process 2 more times.
The pictures that I was putting in the frames were 5x7's.  So then I measured a little bit smaller then 5x7 in the middle of each mat.
Here are my three mats with the centers cut out.
Using my scrap fabric from making the bean bags I cut out a piece that was a little bit bigger then the mat.  I also cut the inside corners just a little bit.
Then I started hot gluing the fabric to mat, folding the fabric over.  I did the outside of mat first.
Here is what my corners look like.
Then I pulled the fabric tight and started gluing the inside.
Here is what the back looked like when I was all done.
Here is the front of the mat.
This is after hanging the frames.  I am waiting for the pictures to come in the mail.  
 
 
