Burning screens

[3Deep]

Question, what color mesh burns the best halftones for you? I notice when I use the yellow mesh color weather it be 156 up to a 230 I get a nice burn on my halftones, just about every little dot washes out fine verses using the white mesh, which I have to wash a lot harder and still don't get good results.  50 to 55 lpi is the problem lpi I get on the white mesh anything below that burns fine on the white mesh.

Darryl
maybe I need to which to all color mesh huh

[Frog]

That's the freakin' point!
Any color, yellow orange, or red (I've seen 'em, all) cuts down on light scatter and undercutting by absorbing some of the light.
Each color could have its own ideal exposure time though, often half again as much as white, so run a step wedge or calculator test exposure.
160 (or 156) seems to be the break-off point with many as to whether to go dyed or not. In fact, from some folks, it's hard to find 160 dyed

[ScreenFoo]

You could only pry my Ultra-orange Hitech 125 mesh from my cold dead hands...   

[Frog]

And I have to say, the red was really more of a magenta 

[inkman996]

I dont bother burning halftones on any white mesh. Except for special effects look like large and in charge halftones which is rare. I have all yellow mesh from 190 up to 305.

We used to use deep orange mesh, it burned great halftones but burn times were much longer as well.

[Gilligan]

How much would yellow change your exposure time on a 156 mesh?

[Frog]

No set answer, but on my screens, with the yellows that I have, a 30% increase. Certainly a good starting point for your own test.

[Gilligan]

Testing is for pussies!

That sounds like when I hear bands say "they are going practice".  I'm always like, What? Don't you guys have any gigs?

The stage is where you practice!

[Frog]

You are tempting fate and daring an appearance by a truly scary character

[Gilligan]

We will commence the experimenting after the 4th of July when I get my new washout booth in my new place.

Though, I'm quite upset right now that I don't think the landlord owns enough property for me to stick a connex box in the back of the shop... still up in the air and ONE small option if not.

[Frog]

Step wedge man tips his goggles to you since he has no hat.

[Chadwick]

I use a one-setting fits all for my exposure times now.

I did set it up for the finest half-tone dots I can successfully expose, while still getting a proper burn/washout,
with, my standard screen coating method, emulsion, yadda yadda.
And of course, I based this on the yellow mesh we use.
( gotta limit the variables or you'll chase your tail )
As I said though, most other things had already been sorted, and I was adjusting only one variable.
Anyhow,
With this new timing in place, the white mesh ( no tones, solids, 80 and 110 stuff ) still exposes just fine.

And it's a damn good thing, since the timer set has been broken since we moved last, lol.
( gotta get that fixed come to think of it )

It took an afternoon, several screens, and telling everyone to leave me alone for awhile.
Results may vary.

I had a proper exposure calculating positive ( is that a step wedge? ), but I wound up using a thing of my own design,
simplified, I suppose, but it nails everything I do art-wise for screenprinting, and worked great.

It could be refined a bit more, but for the most part, I haven't changed a thing in about 5 or 6 years now.

Maybe that helps?

[Frog]

Who can argue with success? Some emulsions have a wider latitude than others. Couple that with a limited number of different meshes, and you could be onto something. Perhaps not optimal exposures but as the hipsters said while tuning their instruments back in the day, "close enough for jazz".

For a long time I used pretty much only white 110's and yellow 160's, and they did have the same exposure times.

And yes, your exposure calculator positive is a one step step wedge test. Some do believe though, that a test made with the same media generally used makes even better sense.
Like you, some of us don't mind fudging a bit though.

Let's just hope that Step Wedge Man (or Exposure Lad) doesn't take offense. 

[MrBreeze]

The only constant is change...We just replaced our exposure table glass with the low iron variety (very cool stuff) and replaced the exposure lamp at the same time to cut down on the amount of variable changes.  We did a step exposure test to re calibrate our settings. Every day your exposure lamp(s) get a little weaker depending on how many hours of use they have on them.  The performance deteriorates gradually, but it does require monitoring for increasing exposure times. Plus as stated earlier mesh counts and mesh color have an impact as well.  We do a variety of work on screens from 86 count mesh (athletic number printing) up to 305 for printing on vinyl.  It really helps to keep good notes in a log to help with your various needs.