Where can I buy a frame to fit my print?

It is possible to frame a print with or without a mount, however, the advantage of a mount is that it prevents the print from touching the glass/acrylic sheet where condensation can build up in humid environments.

Some good-looking frames are available for the square 8" x 8" and 12" x 12" sizes on sites such as Etsy, Amazon or eframe. 

The 11"x19" Gower prints could be framed in a 16" x 24" frame which are available ready-made but you would need to get a mount cut for them.   

If you find it difficult to find off-the-shelf frames that you like, it might be better to have your prints framed professionally by your local framer.  This is more expensive but does add a layer of personalisation and it can be fun to choose your own mount and frame.