An interesting way to use mason jars is to make it into a one-of-a-kind picture frame. The clear jars would be best for this, and by pouring olive oil (try to avoid the garlic kind — could get stinky!) in the jar with an upright picture, you can get a sepia effect and a new way to display your pics.”
Great instructions HERE
Do It And How 
This is a wonderful gift,
How long does the oil stay without going rancid?
Can olive oil be substituted with cooking or vegtable oil?
I’m not finding too much as far as your questions… anyone else out there tried this? All comments appreciated to help this reader!
Yes Kat…follow this link…http://augandeverythingafter.blogspot.ca/2009/08/diy-vintage-pictures-and-mason-jars.html ….. I personally think olive oil would be too expensive for this project.
How do you get the pictures to stay in place?. Do they need to rest near the back or front of picture?
What is the purpose of the dried flower? Is it necessary to include?
The original crafter used the dried flower to hold the picture in a more forward position. Hope that answers your questions!
Is there any other type of oil to use? The vegetable oil looks like urine and its for the centerpieces for my sons graduation party…..