Greetings,
I'm a long-time letterpress/litho printer, just starting in screen printing. And I have a lot of questions!
My first challenge has been to create a fine line screen, using Chromaline SR film and 305 mesh screen.
According to the 21 step scale, exposure to achieve "clear" area at step 7-10 is 30 seconds (units, on my NuArc
unit w/light integrator). But I've had difficulty getting the film to adhere to the screen . . . . it has applied better
with an exposure of about 16 seconds. So I'm wondering if underexposure is better - am I over-hardening the film at the longer exposure?
Next question is abrading the mesh . . . how much is enough? And how do you tell?
And, finally, I have printed a few test sheets (black, non-textile ink on white process blanks), but have found that the screen tends to "fill in" or "clog" after a few impressions, even on larger type (24 pt or so).
Any info or advice is appreciated!
Beginner seeking info/assistance w/screens, printing
Moderator: Moderator Team
Re: Beginner seeking info/assistance w/screens, printing
But I've had difficulty getting the film to adhere to the screen . Next question is abrading the mesh . . . how much is enough? And how do you tell?
Ok if I understand this correctly your film is not sticking to you mesh. Are you using a pre prep before appling the film. And as for abraiding your mesh I never do abraid, I dehaze my new screens before appling the pre prep and film. Make sure your film is dry before exposing the film. What watt of exposure lamp are you using? I have an Olec with a 5000 watt lamp and I expose my CX film at 85 units. True we are using different films but 16 units seems really fast. With your 21 step gauge I always shoot for a hard 7 that means everthing from 2 to 7 is still there after developing the screen and 8 through 21 washes out. As for your printing issue I would try to thin the ink a little start out at 10% and go from there if 10 helps but still a issue add more thinner but I would not go more than 20% or you will shock the ink. I hope this helps please keep us posted.
Ok if I understand this correctly your film is not sticking to you mesh. Are you using a pre prep before appling the film. And as for abraiding your mesh I never do abraid, I dehaze my new screens before appling the pre prep and film. Make sure your film is dry before exposing the film. What watt of exposure lamp are you using? I have an Olec with a 5000 watt lamp and I expose my CX film at 85 units. True we are using different films but 16 units seems really fast. With your 21 step gauge I always shoot for a hard 7 that means everthing from 2 to 7 is still there after developing the screen and 8 through 21 washes out. As for your printing issue I would try to thin the ink a little start out at 10% and go from there if 10 helps but still a issue add more thinner but I would not go more than 20% or you will shock the ink. I hope this helps please keep us posted.
Re: Beginner seeking info/assistance w/screens, printing
Instead of capillary film try some good liquid emulsion that will handle your halftones.
I've never worked with capilary film, but the only time I've ever wanted to was when I needed super thick stencils for high-density print effects at any rate you would use it on 110 mesh or under, certainly not 305.
Tell your supplier what you want to do. I like Ulano TZ emulsion for just about everything.
I've never worked with capilary film, but the only time I've ever wanted to was when I needed super thick stencils for high-density print effects at any rate you would use it on 110 mesh or under, certainly not 305.
Tell your supplier what you want to do. I like Ulano TZ emulsion for just about everything.