how to mount photos on foam board

 This is probably the easiest tutorial ever and I think the results are quite stunning.  Here's what you need to get started:
foam board in black or white (I bought mine at Hobby Lobby for $5.99 minus 40% off with coupon)
pencil
a sharp exacto knife
spray adhesive
pictures
sticky tack (optional for displaying)

1) All you do is lay the photo on the foam board face down and trace with a pencil.  (tip: put the picture slightly and I mean slightly off the edge of the board so you won't have the edge of the board showing on the sides of the photo.  i.e you want the photo and foam board to be the exact same size)

2) Now take your exacto knife and follow that line.

3) Next lay out some scrap papers or cardboard and spray your foam board with the adhesive (make sure to get an even coat and take special care to get the corners.  You don't want the edges to come off. 

4) Quickly before the adhesive dries carefully line the photo up on the foam and flatten and smooth with a clothe (or your shirt sleeve if you're like me). You can adjust the placement some but not a lot so take your time getting it in the right place the first time.

5) Like I said the adhesive is pretty awesome and dries quite fast so you can basically hang them up minutes after finishing.  This is perfect for super impatient people like me.  :)

 I love change.  That is why I love this mounting option because they are light and can be hung with only sticky tack.  That means I can rearrange on a daily basis with no holes to cover and if they are crooked it's such an easy fix. I think I moved mine 15 times to figure out how I liked them best.

Here's the side view.  See... simply, clean photos that make a gallery wall a cinch.  And it's very inexpensive as well.  Good luck!