How to use a screen printers tension meter.

[@maksymveres422]

what is the normal tension for manual printing? Thanks)

[@RichardThompsonCA]

I've read the minimum is 15, anything below that and the screen should be replaced. The screens that I buy usually come in around 22. I've read that the really fancy ones, like the roller frames or eco frames can reach 35. I think if you print a lot of tiny halftones, any movement of the mesh while printing would cause them to smudge, so that might be a reason to get the highest tension possible. I stretch my own sometimes and they come in around 20-22. Even if the machine was capable I couldn't get higher tension than that because the mesh starts to rip at some point.

[@maksymveres422]

@@RichardThompsonCA Thanks a lot for your detailed answer! My screens are about 19 newtons. As I know. 43, 62, 77, 90 European numbers of mesh. For manual printing is ok. But you are absolutely right, for detailed halftones, tension should be much higher! With one Color half tone, 30-40 lpi, I also worked good on 19 newtons mesh

[@umarfarook1971]

Most screen printers say that the screen tends to lose tension over time. My question is: does it loosen the tension even after exposing it? If so, then the registration might miss right. Then how do you prevent it?

[@RichardThompsonCA]

I don't think you could get an accurate tension reading with emulsion coating the screen, it's going to throw off the results, I only test them uncoated. Having said that, I don't think exposing them changes the tension though, the reason I think they lose tension over time is from actual use. If you have off-contact set on your screen you are essentially stretching it every time you run the squeegee over it, and I think that's what causes it to lose tension. The polyester mesh must stretch a bit shortly after the screen is first made, but I think that maxes out after a while and the rest of the stretch is from use. It would be an interesting experiment though, start with two identical screens, test the tension on both and record it, use only one screen for a year and let the other sit unused for a year, then measure both again. I wonder how they would compare? The pro's recommend you select a set of screens for your job all with very similar tension. That way you shouldn't have any registration issues between colors.