Halftone dot size for gradient

[Dochertyscott]

Hey,
So I did this job yesterday for a client which was a basic gradient through a logo.
White base, with a blue gradient and some blue text.
There was a pocket logo @100mm wide and a back print @ 280mm
We used a 55 lpi dot for the blue.
59s white, 120 blue halftone. Mesh. (Metric units)
White p/f/p/f blue p on a manual press.
The end result was perfect but I did have to wipe the blue screen every round (6) in order to keep the dots nice which wasn't ideal. Especially if it had been a large run. (Ended up only being 15 units)
What dot size would Others use for a perfect gradient like so to avoid dot closing in in places?
I don't have a photo of the print as I'm away from the shop but have a look at the client mocks to get what I mean.
http://queenstownscreenprinting.co.nz/qt-conference-video/2014/2/5/pricing-and-mocks
Password= video

[blue moon]

43T = 110 Threads per inch
54T = 135 Threads per inch
64T = 160 Threads per inch
77T = 190 Threads per inch
90T = 230 Threads per inch
110T = 280 Threads per inch
120T = 305 Threads per inch
140T = 355 Threads per inch
150T = 380 Threads per inch
165T = 420 Threads per inch

[blue moon]

Hey,
So I did this job yesterday for a client which was a basic gradient through a logo.
White base, with a blue gradient and some blue text.
There was a pocket logo @100mm wide and a back print @ 280mm
We used a 55 lpi dot for the blue.
59s white, 120 blue halftone. Mesh. (Metric units)
White p/f/p/f blue p on a manual press.
The end result was perfect but I did have to wipe the blue screen every round (6) in order to keep the dots nice which wasn't ideal. Especially if it had been a large run. (Ended up only being 15 units)
What dot size would Others use for a perfect gradient like so to avoid dot closing in in places?
I don't have a photo of the print as I'm away from the shop but have a look at the client mocks to get what I mean.
http://queenstownscreenprinting.co.nz/qt-conference-video/2014/2/5/pricing-and-mocks
Password= video

'not having worked on the manual much, I am only guessing here, but how tight was your 120? If it's loose or you are pushing too hard, you'll stretch the mesh and smear the print.

pierre

[mimosatexas]

I find that for doing tiny dots close together on my manual, especially with something like a 305 mesh, I will soft flood like I would with waterbased, so ink covers the stencil but isnt pushed into it, then I do a very fast, very vertical angled stroke with good pressure and the dots are very clean.  Might try adjusting flood and stroke angle and pressure.

[Screened Gear]

When you do fill in the dots it is from a hard flood or a too soft of a print.   If you see it starting to fill in just don't flood the next print or two and that should get you back on track. Unless you really over filled and then you will have to clean the screen. Soft flood/ hard print. Do a push stroke and that will make it easier also.

[Dochertyscott]

I didn't bother flooding had a nice amount of ink in front of squeegee to try keep it cleaner which helped.
Perhaps it's tension, I'm unsure how tight. I must try and get some shur loc frames.
Probably not idea being a static frame. I'll try a faster print stroke next time.
So 55 lpi as a dot is generally good for gradient? Any larger and it would look a bit obvious for a small pocket logo in my opinion.

[Dochertyscott]

Cool, I'll put all these tips to practice and see how I go. In hindsight maybe even more off contact would have helped.

[Screened Gear]

I didn't bother flooding had a nice amount of ink in front of squeegee to try keep it cleaner which helped.
Perhaps it's tension, I'm unsure how tight. I must try and get some shur loc frames.
Probably not idea being a static frame. I'll try a faster print stroke next time.
So 55 lpi as a dot is generally good for gradient? Any larger and it would look a bit obvious for a small pocket logo in my opinion.

If your not flooding then its too soft a squeegee, to thin a ink, or not enough downward pressure to keep the ink from going under the gasket of the stencil.

[Frog]

So 55 lpi as a dot is generally good for gradient? Any larger and it would look a bit obvious for a small pocket logo in my opinion.

Small areas like this are difficult to make as smooth a transition as you'd generally like because, even though the dots are fairly small, a pocket sized version has fewer dots filling the same space as a full sized version would.

[Dochertyscott]

Union mixo inks which I find to be reasonably thick. Squeegee was a 70/90/70 and reasonably new.
I think I need to pay closer attention to mesh tension. Rather than a tap with fingers I should probably get a tension metre. And some retensionables. Especially for when moving into automatic.
I defiantly haven't mastered the push stroke and in most cases do 2 or 3 pulls especially if no base. Other than for halftones. I think that's why I haven't stuck with trying to master the push stroke. When I push I cnt clear the mesh and then there is then no ink in front of the squeegee to go pushing again. Different topic but something I struggle with. Should lift screen and re flood?

[blue moon]

mixo is not designed for halftones. My suggestion would be to try the Ultrasoft or even better, the Unimatch series of inks. Halftone printing requires ink that is designed to hold the dot shape rather than flatten out.

pierre

[Dochertyscott]

Brilliant, thanks mate.
I love this forum.

[Screened Gear]

mixo is not designed for halftones. My suggestion would be to try the Ultrasoft or even better, the Unimatch series of inks. Halftone printing requires ink that is designed to hold the dot shape rather than flatten out.

pierre

Correct me if I am wrong but mixo mixing system makes maxopake inks. If you want ultrasoft inks you mix in 50% softhand base. I believe it's in the union ink pamphlet that you get with the kit.

[Dochertyscott]

Hmm, I'll have a look, I know I can buy ultra soft union ink in the pottle but it could be just reduced down.
Is there a difference between using plastisol reducer and soft hand base?

[Screened Gear]

Curable reducer and softhand base effect ink differently. Someone else can chime in on the science of it. To make mixo inks ultrasoft inks you have to use 50 percent softhand base. I have mixed it more than 50 % for printing on whites. Curable reducer will make the inks flow easier it breaks down the bonds of the ink. You don't need much. I was told if you use curable reducer and the ink sits for a long time it has the opposite effect. It will make the ink bond and be much harder then if it didn't have the reducer. Only saw that ounce with a white ink that I mixed a lot of reducer into and let it set for months.

Back to you problem. All inks can print halftones. You just need a ink that flows well and can hold its shape after printing. They all can do that on a 2 color job with the halftone screen being second or with flashing between colors. Not sure your experience level but with good technique you should be able to do it.

What press are you using? Does it hold tight registration. On a 120 (305) mesh screens the tension would not matter to much to print a one color on a PFPF white. Tension matters more for registering screen to screen. Even a sloppy screen will print dot on dot to itself. That is if your even printing more than one stroke per shirt with the blue.