Group
FAQ (Frequently Asked Questions)
Printing Solutions
Mesh
Choice of mesh
Mesh selection and datasheets of Sefar mesh
Questions about screen printing mesh
How does the mesh nomenclature work?
Why is dyed mesh used?
Yellow-dyed mesh prevents light undercutting of the film positive during exposure
When UV light strikes a yellow thread, only yellow light is reflected – which does not affect the emulsion
Dyed mesh should always be used for printing fine lines, text and halftone images
When exposing with CtS (Computer to Screen) the impact of dyed mesh is considerably reduced
What is the significance of the weave?
Weave describes the way the warp and weft threads are interwoven
Sefar uses plain and twill weaves
What is mesh opening?
What is the maximum resolution for a given mesh regarding lines?
What is the maximum resolution for a given mesh regarding half-tones?
Stretching
Questions about mesh stretching
How taut can a mesh be stretched?
This depends on the type of fabric, thread count, thread diameter, the mesh size, and the stretching system used.
When should a SEFAR 2 or 3A one-circuit system be used?
The one-circuit systems are suitable for frame lengths up to 150 cm
When should a SEFAR 2 or 3A two-circuit system be used?
The two-circuit systems are appropriate for frame lengths exceeding 150 cm
What is a SEFAR long-stroke clamp?
A regular SEFAR 2 or 3A clamp with an extended piston stroke, in order to stretch large screens
How is mesh tension measured?
We recommend using a SEFAR Tensocheck 100
How to check the screen tension?
What are the possible causes for loss of tension?
Stencil-making
Questions about stencil-making
Why is it necessary to pre-treat mesh before coating it with emulsion?
What is a step exposure?
How to make a step exposure?
What problems can occur with stencils with direct emulsion?
What is the correct coating thickness?
Half-tone
Questions about half-tone printing
How must films be angled in 4-color printing?
How can I avoid moiré interactions between the mesh and the film?
What is a printing process line?
What half-tone rulings can be printed?
Printing
General questions about screen printing
What are the possible reasons for color shifts within a print run?
How can the snap-off distance be measured?
What is the relationship between 'mesh distortion' and the snap-off distance?
FAQ
To help you find answers faster, we have subdivided the FAQ into separate sections concerning mesh, stretching,stencil-making, half-tone and printing.
Sefar AG
Hinterbissaustrasse 129410 Heiden – Switzerland
Phone
+41 71 898 57 00
Fax
+41 71 898 57 21
