# Jagged or Shark tooth edges



## funkmaster (Jan 27, 2007)

I've been screen printing for a little over a year off and on. I recently started using an established professional screen printer and their prints blow mine away. I've notice the main problem with my prints is that they are jagged on most of the edges of the designs while the pro's prints are relatively smooth. My prints come out ok, but look unprofessional when compared. Any ideas why i get these jagged shark toothed egdes? I use a 110 messh and union plastisol ink on 100% 6.1 oz cotton shirts. Do I need to increase my mesh count to get better detail? Thanks!


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## SilkscreenQueen (Apr 7, 2007)

Try using a harder squeege. Maybe you are puting too much pressure down during the swipe. Maybe some off contact would help, like 1/8 of an inch. Are you printing next to (or on top of) another color? If so, an under-flashed image will produce jagged edges. We use 110 mesh for shirts that are a light color w/ dark ink, and an 83 for dark shirts w/ a light ink. And a 125 for finer detailed images.


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## rusty (Feb 9, 2007)

I use a 156-mesh for just about everything. But jagged edges sound like you are not starting with a good image to burn. Are you using low resolution images? When you blow up a low-res image to put on a T-shirt you get the jagged edges. Do you see the jagged edges in your transparency, or does it have smooth edges.


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## Fluid (Jun 20, 2005)

Rusty nailed it . Use a higher mesh. The course mesh of a 110 is causing your saw tooh edges.


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## seibei (Mar 17, 2006)

I'd say use a higher mesh, for one, and two, make sure your film positive is dark and crisp enough - a sawtooth can also be caused by improper exposure, right?


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## feilong (Jan 23, 2007)

all the advice above is great, but look at your image on your screen and see if you are experiencing saw tooth on it. f the film positive looks OK and your are using the right mesh then it is in your exposing method on your screen. Improper vacum or space between the film and screen when you are burning your image will cause saw toothing. What kind of exposure unit are you using?


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## funkmaster (Jan 27, 2007)

feilong said:


> all the advice above is great, but look at your image on your screen and see if you are experiencing saw tooth on it. f the film positive looks OK and your are using the right mesh then it is in your exposing method on your screen. Improper vacum or space between the film and screen when you are burning your image will cause saw toothing. What kind of exposure unit are you using?



thank you guys for all the great info...all of it is much appreciated.

I use vector images, out of illustrator...they look fine when printed on my transparency.

Yes, I am printing on dark shirts with white ink. I get the shark tooth look after I flash and apply a second layer of ink.

I have a homemade exposure unit, halogen light about 1 foot from the image which is pressed down to the screen by a 1/4" piece of glass.

I've noticed more that when I flash, and add a second layer of ink, that's when I get the jagged edges the most, more than if I do it with just 1 layer of ink on a lighter garment.

I haven't used a higher mesh screen, but I think that is my next step...along with double checking my image on the computer.


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## rusty (Feb 9, 2007)

If you are still having trouble, maybe you could post a picture. That would help the troubleshooting process.


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## feilong (Jan 23, 2007)

so you say this appears after you flash and lay the second layer of ink. Is it already there just once you lay more ink down it's easier to see? if it only appears after you flash and print your second layer it could be the way your pullin the squegee. Are you pulling in one continious stroke with the same constant pressure without interuption?


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## RichardGreaves (Nov 7, 2006)

funkmaster said:


> .... the main problem with my prints is that they are jagged on most of the edges of the designs while the pro's prints are relatively smooth. ..... Any ideas why i get these jagged shark toothed egdes? I use a 110 messh and union plastisol ink on 100%


If your coating doesn't create a film across the surface of the mesh, the stencil edge will conform to the shape of the mesh. No gasket edge, no smooth sharp image printed.








Mr. Bad








Mr. Good

This is done with capillary film of multiple face coatings to prevent ink escaping where the stencil edge doesn't trap it.

It could also be your positive. If you do not use a Postscript output device, your image edges could be jaggy to start with.

Test this. Take a piece of 2" masking tape and put in on a cutting board or glass. Cut out an irrugular circle. Place the tape in the corner of a screen you are going to print. This tape is 'perfect film stencil', and should print with a nice sharp edge.

Higher mesh count will work wonders, but I want you to consider what actually controls the 'edge' of the image - The Stencil.

Try my masking film trick on the coarsest mesh you have. It will have a sharp edge. Keep that in mind when you coat it next time. You have to fill the holes first, then let it dry and watch as 65% of the emulsion (the water) evaporates and the stencil shrinks and takes on the shape of the mesh it dries on.










Capillary Film - Careful, don't cut yourself.


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## funkmaster (Jan 27, 2007)

feilong said:


> so you say this appears after you flash and lay the second layer of ink. Is it already there just once you lay more ink down it's easier to see? if it only appears after you flash and print your second layer it could be the way your pullin the squegee. Are you pulling in one continious stroke with the same constant pressure without interuption?


yeah, easier to see after the second coat...i try to alwasy use constant pressure....how about squegees? i've seen squared tips and rounded tips, what does everybody generally use? does that make a difference?

also, i'm going to try the tape thing too....THANKS again everyone for the help!


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## Fluid (Jun 20, 2005)

post a pic of your saw tooth prints. A good close up will help. Are you cleagint eh screen/stencil when printing your second pass/print?


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## Solmu (Aug 15, 2005)

funkmaster said:


> how about squegees? i've seen squared tips and rounded tips, what does everybody generally use?


I use both, depending on what (and how) I'm printing. I can't imagine ever using a rounded blade for off-contact printing though (although I can't say I've actually tried it).



funkmaster said:


> does that make a difference?


I doubt it would make a difference to sawtooth, but it certainly affects the print.


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## Fluid (Jun 20, 2005)

a rounded squeegee will dump more ink than an angled or square one when used properly.


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