# Help with ink cracking



## shatteredsoul (Oct 11, 2012)

Hey im new to screen printing so please forgive my lack of knowledge and terminology.

I have recently been trying to start converting my original heat pressed vinyl designs over to screen print. I got a printing machine and the screens and have been using "permaset water based inks" as i find it much easier that using some of the chemical inks.

ive also got a heat plate which ive been curing them under at around 160 degrees for 2 minutes as stated on the ink sheet.

ive done 5 test prints on t shirts and they look fine, but if i pull the t shirt apart around the design the ink is cracking. Ive had them through the wash 4 times and they all look fine unless you start stretching the material like so:



















I must be doing something wrong and if so could anyone please help me out? id like to stay with water based inks for ease and curing temperature.

Thanks for your help


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## splathead (Dec 4, 2005)

The way to avoid ink cracking when you stretch the shirt is to not stretch the shirt. 

All white or opaque ink will crack if stretched. If you make the same print with standard black ink on a white shirt, it won't crack.


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## shatteredsoul (Oct 11, 2012)

haha that is very true! i mean they sit and hang fine on the t shirt and dont look cracked unless as i say you start playing with it and stretching it.

Yer thinking about it now the black ink on white T shirt is fine, also felt like it went deeper into the t shirt as well rather than sitting on top. Could the ink be watered down a bit to push it into the fabric a bit more or is that just stupid.

Cheers


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## HardEdge (Oct 19, 2012)

Watering it down will affect the opacity of the ink, so add sparingly if at all. Also, the white ink on darks is supposed to sit on top of the shirt, not crush into the shirt to achieve maximum opacity. You could try using Matsui's 301 stretch white. It is water based, very opaque, and is Very Stretchy. We have printed it on compression tees ( stretchy spandex, cotyon blend ) and it can stretch to 150-180% its original size before it cracks when printed and cured correctly. You could also use any plastisol and put stretch additive in the ink, and it will easily double in size before cracking when properly printed and cured. All highly pigmented inks will crack eventually. This is because the high pigment to binder ratio.


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## shatteredsoul (Oct 11, 2012)

Cheers, That's fine i wont bother watering it down then, i did try and use plastisol ink but found it was really hard to clean the screen and the screen cleaner i used ended up melting my washing station handle.

Does make sense about the ink sitting on top etc 
Will have to give that ink a try as it sounds like it will give me that little bit more flex which would never be a bad thing, unless of course its very expensive.

What sort of temp does plastisol ink need curing at? is it lower or higher than water based?

Thanks again


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## HardEdge (Oct 19, 2012)

Most plastisol cures around 320 degrees. It might help to buy a IR temp gun at Lowes, Harbor Freight Tools, Home Depot. HFT has the best prices, around $20 - $30. This little tool will help you sleep at night after the order is out the door. Use it often on every order. You will need to make sure the entire ink deposit hits the 320 - 330 range. The surface temp will be closer to 340-350 to be safe. It all depends on dryer type, temp, and dwell time. If the shirts are 50/50, or 100% poly, I would use a poly white / low bleed ink to keep dye migration / dye subbing from ruining your day. Red 100% poly is the worst. Good luck Jo.


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## shatteredsoul (Oct 11, 2012)

sorry dor the late reply, i did buy one of those guns but the realised it was way off so have chucked it away.

ive made the dryer myself out of a old t shirt heat press, seems to be curing the ink but would like to try some of the Matsui's ink but as of yet have not found a uk supplier.

thanks


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## Printavo (Oct 7, 2007)

I don't quite remember what we did in our shop to fix cracking but try higher heat and lower heat. Gauge what happens and let us know.


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## tman07 (Nov 14, 2007)

I'm not that familiar with water based ink, but ink pulling apart is usually the result of under curing - 
what was the problem with your temperature gun - they usually are very accurate


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## shatteredsoul (Oct 11, 2012)

I will try curing them for longer and see what happens. As said earlier its only if you physically start playing with the design and stretching it, but just wanted to cover my bases.

i bought like a £15 temp gun and tried it alongside my heat prob i have and it was out by about 30 or 40 degrees lol so threw trust out the window haha.

Cheers


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## HardEdge (Oct 19, 2012)

You might check your temp probe. If your heat gun is off that much, it could be your probe. They are accurate to 5 deg in most models. Put your probe in boiling water. If is not between 208 and 214, it's your probe, not the heat gun.shoot the water also just to see which one is incorrect. Do not let the probe touch the bottom of the pot, or your reading will be jacked up. If the heat gun is way off, take it back and get a refund or another one.


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## shatteredsoul (Oct 11, 2012)

yer need to test it and find out, shall let you know which one it was, i assumed the heat temp gun was out because it cost £15 and my heat prob was £50 lol, could be broken though.

Cheers


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