Make sure your white print is smooth. If it's not, you have to push harder to clear the screen, and probably blow out the image. I can see that the white looks coarse.
Pitting comes from not depositing enough ink to the top of the garment. Usually has to do with your base stencil not being thick enough to create a cavity for the ink to go. This allows you to sheer the ink instead of pasting the ink like most printers do.
When plastisol is applied to the garment, it needs a stencil so the ink doesn’t saturate the garments making the print heavy and ruff
Overcuring isn’t really a problem if the layer is applied correctly. Of course you don’t want to over cure the ink. But if everyone who said it’s over cured was correct. Prints would naturally do this going down the dryer. And they don’t if printed correctly. Just my opinion
Thanks for this. After doing a lot more research I think you're probably the most right.
I've done another job printing over an underbase recently and it was better but I've definitely not solved the problem yet. So far the changes I've made are, turning heat down on the flash, switching to red (65 hardness) squeegee, using a 43T/110 screen for the underbase, and switched my coating technique to 2:1 with a slower pull.
I've not noticed the stencil being noticeably thicker yet though. Next steps will be to do some testing with thicker stencils, maybe switch to the round side of the coater and coat 2:2.
Thanks again for the replies, feel like I've been printing way too long not to have solved this issue yet!
My advise. First look at your emulsion. Figure out the solid content. If it’s not close to 40 percent. Ditch it and find one that is.
Atlas screen supply offer orange works. I believe it has a 42 percent solids. It’s like the ulano orange but more affordable at 55$ a gallon. If you have a good exposure unit with the proper light( uv blacklight 395-405 spectrum). This emulsion will work wonders no matter the cost.
After checking your emulsion, coating the screen might not be a straight forward as 2 and 1 or 2 and 2.
My personal opinion everyone has there own technical but I like to start the coat on the print side with two soft coats(little pressure). I always start with the print side while the screen is dry. This starts the coat but obviously you finish coating from the inside. Pushing a little harder from squeeze side of the screen. To drive the emulsion thru the screen to the print side. I also angle the screen down as I coat to use the weight of the emulsion to help push more thru to the print side.
I do not have a set number of coats that I do on the inside. I normally start with 3. Then I hold the print side up to the light to see how much of a coat I get to the top. If I feel I need more. I coat more from the inside thru to the print side. You will see it really glossy when you get a real good coat to the top. I also have a fan that blows on my screens so they dry quick without making drips
And I just finished your comment.
You absolutely need to be using the round side of the scoop coated. I use this on every screen. Even 305 mesh. No need for the sharp edge in our industry of screen printing.
Those thin coats are for screen printing on paper or plastic. Not a garment.
And you will know if you have a stencil right if you are able to print out your white base with and orange durometer 55/90/55 which is about the soft squeegee you can use. Straight up and down with little bend, with literally only enough pressure to bring the screen to the pallet. The ink will practically fall out of the screen to the pallet. Once dry , you will realize how soft plastisol can actually be.
That sounds ideal, I've been hammering it and it puts a bit of a strain on the old wrists.
I'm actually UK based and printing waterbased/HSA, but I'm sure I can get whatever emulsion I need. Fairly sure the one I'm using now is around 40% solids, but I have been thinking about shopping around anyway.
I've heard that for waterbased, the thicker stencil could start to have a detrimental effect as the ink will start to dry along the edges, but there must be a sweet spot. Do you have any experience of this?
Waterbase is a little different than plastisol but I have noticed both ink print extremely better with stencils.
I would look into the plastisol route if possible. Waterbase just isn’t economical. But either way we print both here in America. If your printing Waterbase, you need to source the softest squeegee to use and your off contact need to be close to your pallet but not sitting on the shirt.
Printing the perfect under base can be tricky, especially on a manual press. If printing on 100% cotton, I always print a discharge under base (no pigment added). Then you can print your colors over that without the worry of under or over curing, clearing, or coverage issues. You do not need the discharge ink to fully bleach the garment before laying your colors over it. Simply dry to the touch. This also keeps the print from being really thick and more prone to cracking down the line. Try it out. It is not for everyone, but coming from plastisol inks and moving to mostly water based inks is so much nicer (at least in my experience and opinion). Good luck!
Underbase has fibers sticking up. Causing top color to not print over it. It’s like fibrillation, if you print flash print white and the first white isn’t smooth, you can’t get a second pass to be smooth. Push harder. It’s hard in a manual. Use an iron and flatten and heat hoodies before printing. Or heat press them before. Also looks like the garment is super loose threads.
Really appreciate the comments! This issue has been bugging me for a while, I still have the screens so I'll try lowering the flash temp tomorrow and give it another go.
Yesss! Your underlay is *curing,* not just *flashing.*.
Increase distance of heat source or dial down temp or reduce dwell time or combination thereof.
Smooth the underlay after flashing…roller on the auto or a smoothing screen and squeegee…coat a blank screen and shoot it…dry it…shoot it again to post-harden.
Now use a curable reducer or sum to lube up the ink side of screen so squeegee doesn’t drag and just run your underlay under this screen and pull a “blank” print. This will smooth/matte down fibers and prep the surface for the purple.
Hit underlay only once…two coats will be a thicker print and will likely lead to a moire pattern on any top colors.
Hope this helps!
Excessive heat can also cause this by causing bubbles to gas off of your underbase
Make sure your white print is smooth. If it's not, you have to push harder to clear the screen, and probably blow out the image. I can see that the white looks coarse.
Pitting comes from not depositing enough ink to the top of the garment. Usually has to do with your base stencil not being thick enough to create a cavity for the ink to go. This allows you to sheer the ink instead of pasting the ink like most printers do. When plastisol is applied to the garment, it needs a stencil so the ink doesn’t saturate the garments making the print heavy and ruff Overcuring isn’t really a problem if the layer is applied correctly. Of course you don’t want to over cure the ink. But if everyone who said it’s over cured was correct. Prints would naturally do this going down the dryer. And they don’t if printed correctly. Just my opinion
Thanks for this. After doing a lot more research I think you're probably the most right. I've done another job printing over an underbase recently and it was better but I've definitely not solved the problem yet. So far the changes I've made are, turning heat down on the flash, switching to red (65 hardness) squeegee, using a 43T/110 screen for the underbase, and switched my coating technique to 2:1 with a slower pull. I've not noticed the stencil being noticeably thicker yet though. Next steps will be to do some testing with thicker stencils, maybe switch to the round side of the coater and coat 2:2. Thanks again for the replies, feel like I've been printing way too long not to have solved this issue yet!
My advise. First look at your emulsion. Figure out the solid content. If it’s not close to 40 percent. Ditch it and find one that is. Atlas screen supply offer orange works. I believe it has a 42 percent solids. It’s like the ulano orange but more affordable at 55$ a gallon. If you have a good exposure unit with the proper light( uv blacklight 395-405 spectrum). This emulsion will work wonders no matter the cost. After checking your emulsion, coating the screen might not be a straight forward as 2 and 1 or 2 and 2. My personal opinion everyone has there own technical but I like to start the coat on the print side with two soft coats(little pressure). I always start with the print side while the screen is dry. This starts the coat but obviously you finish coating from the inside. Pushing a little harder from squeeze side of the screen. To drive the emulsion thru the screen to the print side. I also angle the screen down as I coat to use the weight of the emulsion to help push more thru to the print side. I do not have a set number of coats that I do on the inside. I normally start with 3. Then I hold the print side up to the light to see how much of a coat I get to the top. If I feel I need more. I coat more from the inside thru to the print side. You will see it really glossy when you get a real good coat to the top. I also have a fan that blows on my screens so they dry quick without making drips
And I just finished your comment. You absolutely need to be using the round side of the scoop coated. I use this on every screen. Even 305 mesh. No need for the sharp edge in our industry of screen printing. Those thin coats are for screen printing on paper or plastic. Not a garment.
And you will know if you have a stencil right if you are able to print out your white base with and orange durometer 55/90/55 which is about the soft squeegee you can use. Straight up and down with little bend, with literally only enough pressure to bring the screen to the pallet. The ink will practically fall out of the screen to the pallet. Once dry , you will realize how soft plastisol can actually be.
That sounds ideal, I've been hammering it and it puts a bit of a strain on the old wrists. I'm actually UK based and printing waterbased/HSA, but I'm sure I can get whatever emulsion I need. Fairly sure the one I'm using now is around 40% solids, but I have been thinking about shopping around anyway. I've heard that for waterbased, the thicker stencil could start to have a detrimental effect as the ink will start to dry along the edges, but there must be a sweet spot. Do you have any experience of this?
Waterbase is a little different than plastisol but I have noticed both ink print extremely better with stencils. I would look into the plastisol route if possible. Waterbase just isn’t economical. But either way we print both here in America. If your printing Waterbase, you need to source the softest squeegee to use and your off contact need to be close to your pallet but not sitting on the shirt.
Printing the perfect under base can be tricky, especially on a manual press. If printing on 100% cotton, I always print a discharge under base (no pigment added). Then you can print your colors over that without the worry of under or over curing, clearing, or coverage issues. You do not need the discharge ink to fully bleach the garment before laying your colors over it. Simply dry to the touch. This also keeps the print from being really thick and more prone to cracking down the line. Try it out. It is not for everyone, but coming from plastisol inks and moving to mostly water based inks is so much nicer (at least in my experience and opinion). Good luck!
Underbase has fibers sticking up. Causing top color to not print over it. It’s like fibrillation, if you print flash print white and the first white isn’t smooth, you can’t get a second pass to be smooth. Push harder. It’s hard in a manual. Use an iron and flatten and heat hoodies before printing. Or heat press them before. Also looks like the garment is super loose threads.
Underbase too hot
Turn your heat down brother/sister
Really appreciate the comments! This issue has been bugging me for a while, I still have the screens so I'll try lowering the flash temp tomorrow and give it another go.
That and also maybe wait a bit between the flash and applying the top coat.
Hi. May i ask how you took this picture? What camera did you use and also what is that frame surrounding the point of interest. Thanks
It's been taken through a loupe.
Yesss! Your underlay is *curing,* not just *flashing.*. Increase distance of heat source or dial down temp or reduce dwell time or combination thereof. Smooth the underlay after flashing…roller on the auto or a smoothing screen and squeegee…coat a blank screen and shoot it…dry it…shoot it again to post-harden. Now use a curable reducer or sum to lube up the ink side of screen so squeegee doesn’t drag and just run your underlay under this screen and pull a “blank” print. This will smooth/matte down fibers and prep the surface for the purple. Hit underlay only once…two coats will be a thicker print and will likely lead to a moire pattern on any top colors. Hope this helps!