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screen printing => General Screen Printing => Topic started by: Croft on September 18, 2014, 06:18:43 PM
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Well been printing for years never a lot of sim process stuff though, Have been getting my sep from MYSEPS for a while and have had awesome results, Most jobs were in the 100-500 pc range.
We recently got a 2500 pc order with seps from Scott, worked excellent for sample but wasn't able to hold the crispness with the long run so I have a few questions. Better add were using wilflex inks through 220 mesh
1- do you spot before your hi light white?
2-how often do you need to wipe buildup off screens on average?or at all?
3-what do you use to wipe out and do you do both sides?
Also found out about shirt quality printed a sample on a Gildan tee and looked excellent only looked Ok on an M&O shirt which they went with for cost.
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Is your output(rip) linearized?
That's the first thing I would look at making sure your calibrations are correct
Every sim process job runs different in my shop, when I have more time I'll explain some of the differences between jobs but we have printed lots of 1000+ runs wet on wet through the entire job. Just yesterday we printed 780 pcs wet on wet 10 colors and never stopped to clean a screen but 2 years ago I would be wiping every 100 pcs.
Some jobs we have to wipe every couple hundred pcs due to certain colors I cannot eliminate build up on but that's a problem we are working on right now.
But we print quite a bit of seps from myseps and never a problem on long runs. Check out the what have you printed section - both prints I posted today were 300-500 pcs each and we didn't wipe screens once.
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Tuned in!
Now that we have the auto... I need all the tips I can get!
Made me realize I should have taken more notes along the way!
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We do more WOW than we used to, but can always learn more, if Danny is going to school us im in.
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To answer Crofts questions, we do not flash before the white over and we very rarely have to wipe screens due to build up. We do a ton of sim-process and have it dialed in pretty well but I have been doing it for years and that experience accounts for a lot. If you are experiencing build up I would look into ink chemistry and screen tension levels.
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Customers don't see a press sample until stepped on colors build up a bit on the back of the WOW screens and things start to "mingle" Those first dozen or so shirts are lies and the customer shouldn't judge the run on them. Sepped properly, once WOW starts to blend a bit from getting stepped on it should actually look better and be a truer representation of the art than the first shirts where every color looks like it was flashed.
all just i.m.o. there certainly are more qualified people here to comment, but I stopped showing customers those shirts pretty quick once I figured the above out.
To answer some of your other questions, we use QCM WOW inks and never wipe (up to a couple thousand prints or so) If we did have to wipe it would be with Lacquer thinner as it's fast, aggressive and dries very quickly, and we always have it around for the padprinting and epoxy ink screening we do. We would only ever wipe the bottom of the WOW screens.
Flashing before the last white is hit and miss for us, it depends on the art and just how it looks, often we'll up the hilight white screen mesh to 300 if we plan on printing it without a flash before.
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Not nearly as advanced as some of ya'll, but one thing I can say is higher mesh counts help a lot. 280+ if art allows.
We just ran 3000 front and back and I don't think we wiped screens once. If you are getting a lot of buildup to the point
of contaminating the ink in your screen from below (use to happen to us on certain jobs) you really need to stop and
completely clean up everything, maybe even culling the ink in the screen if it's shifted badly.
Print order can make all the difference, and hard and fast rules don't always apply. Strategic placement of colors/coverages
before flashes can be key. Best of luck!
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Croft,
We find that with today's inks anything lower than 305 mesh just puts down too much ink. Sharp squeegees are a must. Any color that is not printing on the base will cause all kinds of buildup issues. So we usually put everything on a base/halftone base except black. Most of your buildup issues are related to short fiber and the sticky nature of non phthalate inks. Always flash after the black. With all this in mind it is not uncommon to print thousands and only have to wipe the base screen to clean lint off the screen.
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Is anyone spraying the bottoms of their screens with silicon or something like it? I rarely print wet on wet since I am a manual only shop, but I have been doing it more and more on sim process and gradient heavy designs to take advantage of the blending on the shirt, and I have found silicon spray tends to help quite a bit.
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Nope, just a good wet on wet ink.
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Thanks for the replies, I was using laquer thinner to wipe screens , the job was on black so it was white base, light grey, red, yellow hi light white , I was getting buildup on the back of the screens but it wasn't creeping into the image area. I wiped out 3 times on 1800 pcs which I guess wasn't to bad. Maybe I am being overly critical because its for a camera company and I would expect them to be critical of colour.
I believe Wilflex is a good WOW ink
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were you really using Lacquer thinner on the emulsion? I wonder if you were causing it to soften or get sticky..
we rarely use anything other than a few white scrap shirts to wipe screens when necessary...
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We like to flash our underbase, buy the rest print WOW. When visiting Rich Roth's shop to check out his MHM's before we bought ours, he told us, "If you have more than 2 flashes, you're doing something wrong." That always stuck with me, and it's always worked. I started before flashes were developed, so all work was WOW...
Steve
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Is your output(rip) linearized?
That's the first thing I would look at making sure your calibrations are correct
Every sim process job runs different in my shop, when I have more time I'll explain some of the differences between jobs but we have printed lots of 1000+ runs wet on wet through the entire job. Just yesterday we printed 780 pcs wet on wet 10 colors and never stopped to clean a screen but 2 years ago I would be wiping every 100 pcs.
Some jobs we have to wipe every couple hundred pcs due to certain colors I cannot eliminate build up on but that's a problem we are working on right now.
But we print quite a bit of seps from myseps and never a problem on long runs. Check out the what have you printed section - both prints I posted today were 300-500 pcs each and we didn't wipe screens once.
Do you modify your inks at all? What base do you run? Halftone base? I think you mentioned before you run a roller squeegee after your bases? The shirt you sent me pretty much makes me question everything I know about screen printing lol it really is that good! You can't see a base on the inside of the shirt so there's minimal ink "volume" on the shirt even though it has a bajillion colors in it.
I feel like a video of people showing their ink viscosity would do wonders for me trying to put down just the right base for top colors.
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We've found that when it comes to WOW printing, mesh count and ink are the two most important factors. Keep your mesh counts high, 280+ and if you aren't using inks suited for WOW...forget about it, you'll be wiping screens and having terrible buildup issues. Listen to the one who does the seps, they usually have the print sequence in a particular order, especially guys like Myseps who know what they're doing. If you're sepping a process job with the "seps in a can" programs there is no telling what will happen with print sequence because we've always found the programs to be hit or miss. Sometimes everything is spot on with color and sequence and other times we have to adjust the color volumes and print sequence to get what we want.
Now that I think about it, on sim and spot color WOW printing, which we do a ton of the spot color stuff here, the ink, ink, ink, ink, ink, ink is MUY IMPORTANTE as my printer likes to say. You can use the right mesh counts all day long but with a BAD ink you're going to have issues. But if you screw up on mesh count selection, a great WOW ink will bail you out. Back in the day, 5 years ago or more, we'd do spot color jobs with much lower mesh than we do now and if the ink was good, we wouldn't have buildup issues. But if you have a suspect ink, mesh count can keep issues at bay, bad ink...it's not going to do much but prolong the wiping by a dozen shirts or so.
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If you're image is applicable, maybe try index instead of sim process. Has worked great for us many times. (More forgiving).
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What dpi are you using for your seperations?
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What dpi are you using for your seperations?
55lpi
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If you're image is applicable, maybe try index instead of sim process. Has worked great for us many times. (More forgiving).
Agree, IMO, index is superior, but you need a LARGE press if you are gonna do it a lot. We love it at my shop.
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For spot color WOW, are there colors that hold up to getting stomped better than others? Or is it best to stick to smallest part of the design to largest regardless of color? If the former is true, could one of the WOW pros in the house list some standard colors by their WOW printability? Are there specific colors that should always be printed last (or first) if possible?
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we switched from Triangle Inks to International Coatings and saw a huge improvement wow, reds and yellows seem to be the worst.
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For spot color WOW, are there colors that hold up to getting stomped better than others? Or is it best to stick to smallest part of the design to largest regardless of color? If the former is true, could one of the WOW pros in the house list some standard colors by their WOW printability? Are there specific colors that should always be printed last (or first) if possible?
Certain colors stick more than others so you have to run them later in the print order. Red, yellows, oranges, and some colors that are naturally transparent need to be run as late as possible to avoid issues. Screen tension and ink type also play a big roll. 280 and up mesh, triple durometer squeegees will make a huge difference as well.
One mistake people make is stopping a lot during the run. If you stop you inks on the backs of the screens can tack up from the heat of the pallets themselves. They can also become tacky from cooling down. At this point you have to wipe them down or they will stick and pull up ink on the next few prints.
Danny mentioned it above but linearized films are a must if you want to eliminate saturation issues on press. When working with your sep guy you need to tell them so they can cut down on the % of ink that gets laid down versus a person using linearized films. It will prevent buildup by not laying down so much ink during the run.