Greyscale done as just black and white?

[Frog]

So what kind of coating (3:1, 2:1?) of emulsion should I do on these 200 mesh screens to get the right EOM for these half tone dots?

Except for specific heavy deposits, I coat (and expose) all screens similarly. Shooting for the glisten method you already know.
You may remember that that article even shows examples of dots being better defined with proper (greater) EOM than skimpy methods. That's one of its benefits.

[Gilligan]

I would do 1/1, but thats me...I know my emulsion and how it coats.

Is that how you normally coat even for spot color work?

Just wondering because many people think very highly of the glisten method.  But I have heard discussions of dot gain and such due to stencil thickness.  I don't want to go TOO heavy if there is a potential issue with that.  I would think it would be better to err a hair thin than thick.  But I could be completely off.

[Frog]

What's the issue? You learn your dot gain and compensate either manually in the art creation or upon output.

[Gilligan]

Well, to be perfectly honest... I don't even REALLY know what "dot gain" is.

This is where I wish we had a terminology glossary (I know you linked to one, but I hate opening up more and more pages.... odd that I say that considering I literally have about 80 tabs open right now... but that's my point).

[3Deep]

It depends on what I,m printing that day if its halftone on a 230 mesh I coat 1/1 with the round edge of the coater, 4cp I do 1/1 with the sharp edge.  Most stuff I coat the print side 2 the squeegee side 1 with the sharp edge of the coater.  I will say I don't fellow all the rules that most printers live by, if it works and I get a nice looking print I repeat it on jobs of the same nature.
Darryl

[myseps]

Well, to be perfectly honest... I don't even REALLY know what "dot gain" is.

Dot gain is when you print and the halftone dots expand. You want to try to control this from happening too much.

[Gilligan]

That is what I ASSumed it was, but I didn't want to get too far a head of myself and off running in the wrong direction.

How does one minimize or "learn" this effect?  As I've had experience with ink build up I would think this could get ugly in that sense pretty easily.

[blue moon]

I would do 1/1, but thats me...I know my emulsion and how it coats.

Is that how you normally coat even for spot color work?

Just wondering because many people think very highly of the glisten method.  But I have heard discussions of dot gain and such due to stencil thickness.  I don't want to go TOO heavy if there is a potential issue with that.  I would think it would be better to err a hair thin than thick.  But I could be completely off.

you should be shooting for 8-12% EOM on the sim and 4CP jobs and around 20% on the spot colors. all of this is pretty much useless to you (me too as I am not at that level yet either) at this point in time as you still need to print the test patterns.

as Frog pointed out, coat all your screens the same now so you have consistency and can set your reference points. Then once you know what is going on you can go and evaluate the results if you make some changes. Without having a baseline it will be very difficult to figure out what is going on. . .

Now, go burn the patterns and let us know what you got!

pierre

[inkman996]

You control in the art, the mesh selection, the squeegee selection, the ink OMG i could go on forever! No seriously if you do as Andy said print some halftones as you normally would always print and judge how much your dot gain is. I can tell you already if you are always double hitting black then you want to lower your black percentages to account for that. For instance instead of a 70% black go 50%. A 70% black double hit will almost completely fill in.

[3Deep]

That is what I ASSumed it was, but I didn't want to get too far a head of myself and off running in the wrong direction.

How does one minimize or "learn" this effect?  As I've had experience with ink build up I would think this could get ugly in that sense pretty easily.

How to stop dot gain opens up a hold book of answers, but to give you something quick manual printing #1 squeegee angle #2 print pressure #3 print strokes #4 mesh count #5 inks #6 shirt weave (maybe not so much ), but you can see where I,m going with this.

Darryl

[Frog]

I mostly print pretty simple spot color jobs, sometimes half-toned, usually not. I generally print with 180's and 200's dark on light. With my halftone screens, I often move up to 230's and 260's, all coated to the same glisten method, but obviously with the relatively thinner coating on the finer meshes. (but still with similar EOM percentages.) The higher meshes allow for smaller dots, but over the years I did fine with 160's for many "shaded" halftone designs.

I tend to experience a 10-15% dot gain, and usually compensate in my artwork in CorelDRAW, and output with Ghost. I know that many use a setting in Photoshop to knock back all percentages together at their desired dot-gain, probably something similar in PAINT. I don't know about Illy, and if I'm missing something in DRAW.

As I said, do what I suggested, and see what your dot gain is by comparing samples.

[Gilligan]

Cool... that answers a good bit.

I do plan on doing these things... I'm just at my computer shop fixing computers right now so I can't run these test... but I can get as much knowledge info leading up to that point as I can.

Measure twice cut once right?

[blue moon]

Measure twice cut once right?

actually, the tests are the measuring part!

[Gilligan]

Sure but I have to measure for the test also.

You don't just go out with a tape measure and saw and assume you will make a table.  You have to have a plan first.

[Chadwick]

Got here late, but adjust your art like Dan did.
( this what I would do anyways.. )

If the actual file you have is all low res and anti-aliased, punch out the tones to a proper solid lineart,
you can use curves or levels or what have-you to do this, clean it up,
then add the tones back in. It'll be nice and clean.

You mentioned lower mesh count.
I get away with 40lpi on 150ish mesh all the time, but I use a good exposure unit and I've been at this for awhile.
You have 200 mesh, it should be a piece of cake.

40lpi is a larger dot, and this is one color, so make em round, as opposed to elliptical.

I like 22.5 for an angle, 25 works as well.
Keep your tones between 10 and 70% ( or less if you're worried about press gain ), and giver.

This shirt's kinda old, dirty and such.
Excuse the jpegs, but you should get the idea.
One screen, one stroke, regular old black plastisol.



( printing goofy images helps immensely )

Hope that helps.
Cheers.