DIRECT EMULSIONS & CDF DIRECT-FILMS | Solid Step 7
When you develop the stencil, areas that didn’t get enough exposure to survive development will dissolve with water and rinse down the drain. You want a minimum of a Solid Step 7 that survives and holds in the mesh. More exposure will make your stencil more durable and less will make the stencil less durable.
Stouffer 21 Step for establishing a MINIMUM exposure with a Solid Step 7 on direct stencils exposed on the mesh
The guide numbers are clear on the film so they get 100% exposure. You will know you have a Solid Step, because you won't see a difference between the guide number, (7), and the patch of stencil around it. If you have a 'crusty' step, you know that unexposed stencil on the inside of the screen has broken down and washed away with water. Not Solid!
The great thing about a Stouffer 21 Step Transmission Gray Scale is that it only costs from US$6.00 to US$12.00 and should last a lifetime. The 21 Step is a real photographic positive with 21 steps of opacity that simulates 21 different exposures - with one exposure. Much faster than than a manual step test, where you have to move a piece of cardboard or Rubylith to block UV energy.