It took me awhile but I figured out a game plan for a memorial poster. I'm using a foam board and I plan to lace ribbon around the exterior for a handmade "frame".
Is there a way I can attach the photos to the board but still be able to remove them later? Sometimes repositional adhesives dont stick to the surface.
Thanks for your help! 
I'm trying to visualise what you are describing. So if my answer is total rubbish, I haven't completely grasped what you mean. But how about covering the whole board in ribbon, interlaced diagonally or straight and clipping your photos to the ribbons? You can use the color of the ribbons to give extra visual interest and/ or underline the mood you want to convey. Good luck with your project
I was thinking about that but I ran out of ribbon and I already used up my budget, LOL! But that was an awesome idea, thanks for your input Lilian.
You could get the acid free repositionable/temporary "glue" dots, just make sure there isn't a time frame before they become permanent. I don't think they are too expensive.
Thanks Janet. I think I may have some on hand. Not sure though, lol!
Update, the Memorial board turned out wonderful. Thanks for the input.
I would get some velcro...place the one part of the foam board, and the opposite part on the back of the photos...then you just velcro them on...and take the velcro off the photos when finished.
I'll keep that in mind the next time I make one of these. I smell another memory board project in the works now for sure.