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Originally Posted by Solmu |  | | | | | | | | | Only if "by definition" you are allowing for the thickness of the mesh itself and the (desired) blockout of the stencil. | |  | |  | |
If the stencil touches the substrate, it is on-contact. It makes a bad print if the operator or the press has to pull the mesh out of the ink film. If the mesh doesn't resist the friction of the squeegee, it will move across the surface of what you are printing - ever so slightly, and when you lift the blade, the mesh will snap back (smearing the ink), and after the damage is done, the operator or the press or the mesh will pull the ink and stencil apart.
Demonstrate this by taking a finger and moving the skin on the back of your hand. That is the squeegee manipulating the mesh. Now make a fist and tighten the skin on the back of your hand. Now try to move the skin with your finger.
The longer ink and mesh mingle together the harder it is to separate them - even if it's fractions of a second. That is why I want the mesh to pull itself out of the ink film.
Yes, you have to adjust for ink deposit, mesh tension, ink tackiness. If you don't allow for the thickness of your ink deposit, stencil thickness, blockout, the mesh can't pull itself out of the ink film, right behind the squeegee blade.
By definition, screen printing doesn't work consistently if you print on-contact.
Yes, there are some electronic or ultra-stable images printed with stainless mesh (non-stretchable mesh), that are printed on-contact so there is no distortion and the press must pull the mesh out of the ink film. This is done with custom presses costing tens of thousands of dollars - not a textile press.
There are also printing schemes that use air pressure to transfer ink through the mesh with the top of the screen sealed and pressurized and the hard part is separating the mesh from the ink without smearing.
Areas not printing 
