4 Colour Seperation
4 COLOUR SEPARATION FOR T.SHIRT
SILKSCREEN PRINTING MADE EASY
WITHOUT RIP SOFTWARE.
original image
4 colour halftone separation for t.shirt silk screening, using adobe
photoshop/illustrator/ acrobat
How to correctly expose your stencil using photographic emulsion
In silkscreen printing you need to have a solid black image on your film positive. However, if your image
consists of more photographic gradients and varying tone or when you turn your image to black and white
for your film positive, you will have significant amounts of grey image area which will not properly expose.
So, the best way to screen print photo style images is to use a halftone pattern.
A halftone pattern is a series of dots that vary in size and shape and spacing to create an optical illusion of
varying tones and gradients. The dots are so small that the human eye blends them together so they
appear as smooth tones.
Creating your halftone image use Adobe Photoshop which has a number of filters to reproduce your image
in a halftone pattern that you can use for your film positive. Or you can use Ben‐Day Dots, which are sheets
of dots comic book illustrators use to create secondary colours.
These small coloured dots combined create a third colour. They would be purchased in sheets of sticky
transfers and then applied to your sheets of film in the needed areas to create your shading.
Experiment first with the size of the dots you will be able to print. But the general rule of thumb for
determining correct mesh count to use is 3.5 x halftone line count to get the minimum mesh count e.g. A
65-line halftone image would require a 230-thread/inch (imperial), or metric (cm) 90t mesh or higher. The
higher the mesh count, the better the stencil and the print. Also keep in mind that yellow mesh is often
recommended for high resolution printing with halftones.
When printing halftones using waterbased ink, set your dot size at 32 lines/in, you can print this easily with
any mesh count of 43t‐ 65t. For plastisol or solvent inks set your dot size at 62 lines/in. You can print this
easily with any mesh count from 90t‐ 140t.
1. SCAN YOUR IMAGE OR SELECT A PHOTO FROM THE INTERNET AND SAVE IT IN MY PICTURES. IE JIMI HENDRIX ABOVE.
2. NOW OPEN THE IMAGE USING ANY PHOTOSHOP CS SOFTWARE.
3.OPEN LAYERS AND CHANNELS, EDIT, CONVERT PROFILE TO CMYK.
4. SAVE IT AS A JPEG FILE.
5.NEXT GO TO IMAGE, SELECT IMAGE SIZE, DOUBLE THE SIZE YOU WANT TO PRINT, i.e. IF YOU ARE TO
PRINT A4 THEN SET THE SIZE TO A3. ALSO SET THE RESOLUTION 300DPI, THEN SAVE.
6.BACK TO IMAGE, SET THE THE CANVAS SIZE 50MM LARGER THAN THE REQUIRED IMAGE PARAMETER.
7. PLACE REGISTRATION + MARKS IN THE 4 CORNERS OF THE CANVAS.
8. GO TO FILTER> PIXALATE>COLOUR HALFTONE, IN THE BOX YOU INSERT MAX RADIUS FOR PIXEL ,5.
YOU ALREADY SET THE RESOLUSION AT 300DPI, DIVIDE IT BY 5 = 60 DOTS PER INCH FOR PLASTISOL
SCREEN PRINTING, FOR WATERBASED SET THE RADIUS PIXEL AT 8 WHICH WILL EQUAL 35 DOTS PER
INCH.
9. NOW SET YOUR SCREEN ANGLES IN THE SAME BOX:
CHANNEL 1 CYAN 15, CHANNEL 2 MAGENTA 45, CHANNEL 3 YELLOW 75, CHANNEL 4 BLACK 75
10.IN THE CHANNEL BOX CLOSE THE VIEW ON 3 OF THE CHANNELS BY CLICKING ON THE EYE, LEAVE CYAN
OPEN AND USING THE MAGIC WAND TO SELECT THAT CHANNEL GO TO EDIT> COPY
11.NOW OPEN ILLUSTRATOR CS, CREATE A FILE AND AN ARTBOARD, PASTE CYAN INTO THE FIRST LAYER.
NOW GO BACK TO PHOTO SHOP, UNDO THE MAGIC WAND AND OPEN THE VIEW ON THE NEXT CHANNEL
BY CLICKING ON THE EYE, CLOSE THE VIEW ON CYAN.USING THE MAGIC WAND AGAIN SELECT THE OPEN
CHANNEL AND COPY. GO TO ILLISTRATOR CREATE A SECOND LAYER AND PASTE MAGENTA INTO LAYER 2.
REPEAT THIS UNTIL ALL THE CHANNELS FROM PHOTSHOP ARE INTO SEPERATE LAYERS INTO THE
ILLUSTRATOR FILE.
12. ON EACH LAYER YOU CAN TYPE ITS COLOUR IN THE CORNER OF EACH FILM (AS SHOWN BELOW).
13.GO TO WINDOW AND BRING UP THE TRANSPARENCY BOX, DARKEN EACH LAYER KEEPING THE
OPACITY 100%.
14. NOW YOU CAN OPEN A 5TH LAYER AND 6TH LAYER AND ADD SPOT COLOURS. FOR EXAMPLE
JIMI HENDRIX TEXT WHICH CAN BE PRINTED IN METALIC GOLD.
15. HERE WE HAVE 4 COLOUR HALFTONE SEPERATION WITH 1 SPOT COLOUR WHICH CAN BE
PRINTED IN METALIC GOLD USING A SCREEN WITH A 43T MESH. MAKE SURE YOU PLACE REGISTRATION MARKS ON YOUR ADDITIONAL LAYERS.
ALL OF OUR FILM POSITIVES ARE NOW READY TO BE PRINTED OFF. ILLUSTRATOR WILL ONLY
ALLOW US TO PRINT IN LINES. WE NEED TO KEEP COLOUR SEPS IN DOTS. WE ALSO NEED TO
PRINT OUR GREY AREA DOTS AS BLACK AS WE CAN ON THE FILM SO WE CAN BURN THEM ON
OUR SCREEN. WITHOUT THE USE OF RIP SOFTWARE OR A DIGITAL PRINTER e.g USING AN INKJET
PRINTER EPSOM 4000DX.
WE WILL NEED TO PLACE OUR LAYERS INTO ANOTHER SOFTWARE
STANDARD ACROBAT PACKAGE. THIS SOFTWARE WILL ALLOW US TO TELL THE PRINTER HOW
WE WANT OUR FILM PRINTED, ALSO THE SOFTWARE WILL ALLOW US TO PRINT OUR FILMS
WHATEVER SIZE WE WANT WITHOUT LOSING THE SHARPNESS OF THE DESIGN.
16. THE EASIEST WAY TO DO THIS IS TO PLACE ALL OF THE LAYERS ON THE ARTBOARD INTO
ILLUSSTRATOR,THEN SAVE AS A COPY IN PDF.
17. NOW OPEN THE PROGRAM ADOBE ACROBAT. GO TO FILE AND OPEN YOUR PDF COPY AND OPEN
AND VIEW YOUR LAYERS.
18. CLICK ON THE EYE BALL TO CLOSE THE VIEW ON EACH LAYER (COLOUR SEPARATION). ONLY
LEAVE THE LAYER ON VIEW WHICH IS GOING TO BE PRINTED.
19. GO TO PRINT SETUP.> CLICK PROPERTIES > BEST PHOTO > ADVANCED> BLACK INK ONLY.
20. PLACE DAYLIGHT FILM IN PRINTER AND GO TO PRINT. THIS FILM HAS BEEN SPECIALLY COATED
TO PROCESS HALFTONE DOTS.
21. NOW PRINT EACH SEPARATED LAYER (COLOUR) FILM POSITIVE BY CLOSING THE VIEW IN THE
LAYER YOU HAVE JUST PRINTED AND OPEN THE VIEW ON THE NEXT ONE TO BE PRINTED.
22. NOW YOU HAVE SUCCESSFULLY COLOUR SEPARATED AND PRINTED OFF YOUR FILM POSITIVES
YOU ARE READY FOR CREATING YOUR STENCILS PLEASE SEE OUR VIDEO TUTORIAL GUISE ON
'EXPOSING YOUR SCREENS'.
23. A VIDEO WILL SHORTLY BE PLACED ON OUR WEBSITE SHOWING YOU HOW TO PRINT THIS
DESIGN USING 1 COAT PLASTISOL INKS ON A 6 COLOUR EVOLUTION PRESS. WE WILL SHOW THE
EASY REGISTRATION PROCESS ON THIS UNIQUE PRESS WHICH HAS A FLOATING HEAD.
