Stencils by IMG Marking Group..
These are commercially made stencils created by the IMG Company.
The sizes of the stencils are going to progress from .194"x.313" to .456"x.735"
These stencils are for electrochemical impressions using an etch machine. These will measure approximately 1" x 2 1/2". There is one image per stencil. You should get several dozen impressions from one stencil. You might get a hundred impressions if you don't burn your etches too deeply and you clean them up properly. It's really hard to say. I tend to use a stencil like this for an average of 50 to 60 impressions and then pitch it.
Tip to extend stencil life: Clean your stencil by making an impression on a carbon block through a dampened cotton pad to remove any residue metal. When you are through with the stencil, rinse it with fresh water and blot it dry. Too high of power setting on your etch machine will fry the stencil and shorten the life. Try a lower setting but longer times.