Chromaline's Exposure Calculator eliminates miscalculated exposure time with three kinds of quality checks. An easy, user friendly tool for the novice and the advanced screen maker. Designed to help determine correct exposure time, print quality check and halftone tests. Instructions are easy to understand and very complete.
Bottom Line: At least 90% of stencil failures can be traced back to exposure times. For under $30, this little tool could save you hours of frustration!
It works great once we corrected the way it was put together. I came with the ND Filters taped on the image side where the images are supposed to be directly against the screen. This causes a slight choke which skews the results. For someone with zero or little experience, they probably would not know the difference. I would suggest you correct that problem.
I used this several times on an open area of my screen to me dial in my exposure time. I was about twice as long as I needed to be. Now it's much easier to wash out the image and maintain the detail.