For most applications on an automatic or semiautomatic machine, the floodbar should only slightly contact the stencil during the flood stroke. The shape of the contact edge is a critical factor here. Sharp-edged coaters prefill the mesh with less ink, whereas rounded coaters prefill the mesh with more ink. Using the floodbar off-contact from the screen means you are relying on the ink to flow into the mesh openings on its own, and you essentially give up all control. In all but the most precise applications, these variations are irrelevant.
Consistent setup is crucial, and the only way to get it is through accurate recordkeeping.
Production control cards detailing all the parameters of press setup are the foundation of good process control. A simple rule is to record enough information so that any printer familiar with the machine controls can use your information to set up a job and achieve the required print characteristics without having to ask for more information. In a situation where multiple colors are being printed on the same machine, or several machines are arranged as an inline printing system, the setup characteristics should ideally be the same. Variations will result in changes in image size and ink deposit. Having material on hand to support the production run is a related press-setup concern.