How to keep fine lines from blowing off?

[Gilligan]

My wife sometimes gets a little to confident in what we can hold and will put some super fine lines... maybe like .25 pts.  She just creates without much thought of if we can make the screen.

Well, what happens is the little lines will let loose and become like strings blowing around the screen still attached where they get larger.  This hasn't caused too many problems until the last job we did, it caused some squiggles, not an issue because she created the artwork and it was abstract enough so you don't know it wasn't meant that way.. but I know it wasn't.

I'm coating pretty thick, at least 20% EOM and up to 100% EOM.  So I know it's coated well in the sense that it's wrapped around the knuckles.

Now confessions, I'm doing this on 150s and 158-? mesh as my "high end" right now.  Will have some higher end screens shortly as soon as my buddy finishes my side clamps (which I can more comfortably nudge him once I get his jackets embroidered. )

Chromaline Blue exposed on a MSP 3140 and developed with a cheap pressure washer from about 12"-18".

[Frog]

Underexposed? Too much pressure developing? Too coarse a screen as you have already mentioned.

Also, if you are really designing with .25 pt lines, reversed out, they're going to fill in anyway.

btw, unlike many here, I don't use a pressure washer for my development rinsing, I use a shutoff sprayer nozzle.

[Gilligan]

Good point, they do fill in, I guess I just feel like they should hold.

I'm pretty sure I'm not underexposing... no slime, nothing of the tale tale signs.. but maybe.

The crappy pressure washer does concern me due to it not being consistent and I know Alan's killer pressure washer doesn't have a lot of "pressure" if you put your hand in the stream where as mine will sting a bit... obviously I don't suggest getting close to the tip at all, but at appropriate equal distance is what I'm talking about.

I found I kind of needed a pressure washer because a thick EOM (100%) was taking so long to develop with garden sprayer on "jet" that the screen was breaking down.  Plus a typical 20% EOM screen was blowing out beautifully with that 3140 and proper exposure... blew my mind compared to my crappy DIY exposure "system" I had before.

[alan802]

Each mesh count has a "minimum line thickness/size" that it can hold consistently, just like a halftone dot really.  I don't know the formula right off my head but you have to determine the thickness of the threads and overall thickness of the mesh and emulsion, then divide that by something like 352 to get your minimum line point size for a particular mesh.  I think a 110/80 can hold a .87 point line with an 80 micron eom...according to my fuzzy memory.

[JBLUE]

Too much emulsion, too low of mesh and under exposed. Like Frog said that is just going to fill in after a few prints then you will be wiping the screen.You can do it you just have to step up the mesh count. Set guidelines for the wife until you get the right stuff to do hold that stuff. Even with a high mesh it will be difficult to keep that from bleeding and closing in especially if your squeegees are not super sharp.

[Sbrem]

have your wife make a film with a series of lines of different weights, both positive and reversed out of a block, and test them against your assorted meshes. Get your exposure right, and if you're using a pressure washer to wash out the image, don't get too close... If I'm removing a stencil (which I hardly do at all anymore) I'm right on it; washing out a stencil, I'm a good foot away... hope that helps.

Steve

[Ripcord]

I like to use a minimum thickness of .8 point for positive lines and 1 pt for reverse lines. Even if you can get a skinnier line to hold on the screen, when you print it will fill in (reverse) or will have a jaggededy look to it from the tiny bit of ink creep that would not be noticeable on a bolder line.

Nice bold lines will result in a nicer looking print.

[ScreenFoo]

I think the least conservative measurement is one mesh opening and two threads.  Quite possible with mediocre equipment.

[3Deep]

I,m stuck on washing out with a pressure washer, I use a multi function water sprayers which works great and I find the best emulsion for holding very fine lines and halftones is dual cure, I make the switch a few years back for my process and sim screens.

Darryl

[Gilligan]

Thanks for all the info guys... keep it coming as we are learning a bunch here.  If anyone knows that formula that Alan is talking about the math nerd in me would love to see it.


Darryl, it really comes into play with the THICK EOM, like 100%.  We were developing with the same thing as you were and the top color screens came out fine, then when I hit the Underbase it wasn't developing.  Eventually the emulsion started breaking down (this is PP emulsion which didn't help).  At first I thought I had over exposed or too much heat in my drying cabinet.  Then after it happened again, I realized it was the thickness of the emulsion wasn't allowing it to really "break down" the unexposed parts (this was a large open area).  So I switched over the pressure washer and that helps the water penetrate the unexposed area to get that emulsion to soften up before the exposed does.

I've also since started agitating with my hand more aggressively on these screens and more frequently, you can see the emulsion dissolving a good bit... but it still helps to have that extra penetration, some of you guys know what I'm talking about.

Developing regular screens with the pressure washer just becomes a pleasure and happens super fast.

[Prosperi-Tees]

Not really fine lines but you can see the difference between using a 156 mesh and a 230 mesh, old static frames coated 1/1 round side with Ulano Orange.

[Prosperi-Tees]

Geez those pics are blurry, sorry.

[Gilligan]

Geez those pics are blurry, sorry.

LOL, was just thinking... man your photography skills suck Gerry!  J/K, I get the picture (and a headache).

[3Deep]

I going say now this pic is bad, but you might can see it, I did this a few years back and it was all done on 137 to 156 mesh count screens. those lines are pretty thin in spots
Darryl

[ebscreen]

Darryl's pic illustrates one of the worst offenders of this sort. The super fine serif's on some typefaces.