I have created this frame that is in 3 parts :
1. The base that receives the picture

2. The cap to close this base with a simple system

3. The pattern cover interchangeable

On the sliced document, you will find 2 bases and caps and 8 patterns that I have designed. 
You can create your own and add them to the list.

The base has several use case as you can hang it, add some magnet diameter 6mm in space prepared for it (just stack it in) or use the feet prepred for that purpose