Before You Went LED, What Were You Using?

[alan802]

Update:

So we're burning about 30 screens a day now so I'm getting lots of opportunity to dial in everything and so far we're still struggling with what I consider the basics.   

Chromablue "type" emulsion, 150/48 yellow, 15%EOM: 30 seconds, I'm getting great washout action on the image areas that are larger than our registration marks, it's superb actually.  But my problem is I'm getting overexposure symptoms on the small stuff like our regi marks and art info we put on our film.  So we've got great washout and poor washout on the same screens, under and overexposure, along with a decent amount of slime when wiped with a white shirt, but when you rub with your finger or lightly with a fingernail you don't get any colored residue.  So it's noticeable undercutting.  45 seconds yields great washout still but getting much tougher to get the regi marks out without breaking the stencil outside the image area.  Still slimy.  75 seconds is where we can't get the regi marks out while still retaining any edge definition but the larger images are fine, still got slime.  120 seconds is identical to the 75 seconds except regi marks will not develop at all.

HVP, same screen EOM and variables other than emulsion:  30 seconds and we're getting great washout on small and large image areas, very little slime and barely noticeable on the white shirt, but you can get a faint bit if you rub with any pressure.  The HVP is also retaining the regi marks up into the 100-120 second ranges and on the 120/54 mesh counts you can get some slime but the higher mesh counts with thinner stencils are very workable and we've managed to not have any breakdowns on press with either emulsion.

So the Chromablue emulsion is a double edged sword, it's great to not need to use baby powder, it dries incredibly fast, hasn't broken down on press with the last batch of screens I coated.  But it is not as user friendly and the undercutting is very bad.  The HVP is way easier and exhibits much more exposure latitude and it looks like the clear winner and a no-doubter to use instead of the other emulsions.  I've got a few more screens to burn for the day and I'm going to go to the extremes with burn times, high and low with the remaining screens and report back.

I've got some options on the table now I'm considering.  I won't go public with them as I need to make this decision on my own without any outside influence.  I'd like to share that and get some input but even though most know most of what we're dealing with there are little nuances of our operation that are very different from the average shop so this problem needs to be fixed internally due to those circumstances.  I feel like I have 3 good options and no bad options but even the smallest detail can make a big difference long-term.

[ebscreen]

I will see about getting that for you. Even better send me a file of your own for us to try.

I'll make it even easier and send yous guys a film and a quart of our emulsion. We use SP-1400.
Is there any way for you to test durability after exposure? 

[ebscreen]

It aint always about you.  The typical customer would never know the difference between above average print and ultra high end print unless you show them. So I didn't miss a thing, the context of my post remains that as LED gets cheaper most shops will be using it in a few years. I certainly didn't say YOU would be using it.

Sure. Personally I hate loss of image quality at any point. Some of it is inevitable (fabric weave, etc) and some of it is avoidable. I'll avoid
the avoidable even if it means sticking with dinosaur technology. Hell, the edges of raster text makes me wanna puke though you'll never
see it on the shirt.

If your super high end shop (which remains to be seen) needs the next level go for it. Why are you even bothering in these discussions if your are proclaiming to be so far above this technology?

Why do you feel the need to jump in a post regarding the science of exposure to tell us that as things get cheaper more people will buy them?
Thanks for the economic pearl of wisdom there Captain Obvious, but it has nothing to do with the discussion at hand. And quite honestly, it's more
of the same as far as I've seen on the subject. Plenty of people use cheap toilet paper....

[GraphicDisorder]

Sure. Personally I hate loss of image quality at any point. Some of it is inevitable (fabric weave, etc) and some of it is avoidable. I'll avoid
the avoidable even if it means sticking with dinosaur technology. Hell, the edges of raster text makes me wanna puke though you'll never
see it on the shirt.

Me too, but if the difference doesn't make it to the shirt, then it don't matter much does it? 

Why do you feel the need to jump in a post regarding the science of exposure to tell us that as things get cheaper more people will buy them?
Thanks for the economic pearl of wisdom there Captain Obvious, but it has nothing to do with the discussion at hand. And quite honestly, it's more
of the same as far as I've seen on the subject. Plenty of people use cheap toilet paper....

My original point was about the coming domination of LED was more or less a reply in support of this comment:

LED is here to stay.  As much as I like MH units for there long run durability, we simply rarely see the 90k runs of discharge or HSA here in the states.  So for almost 99% of the US printers with shorter run lengths, LED works just fine.

So again not about ebscreen, but you went on to thump your chest and create extra drama when there was not any to that point. In case you have missed how forums, within threads side discussions happen that may not be fully on topic.  It's not always about you.

[T Shirt Farmer]

Update:

 But my problem is I'm getting overexposure symptoms on the small stuff like our regi marks and art info we put on our film.

Alan do the reg marks wash out OK with pressure washer ? I see some of the same issue with HVP but a quick power wash opens everything right up for me.. I am relating this issue it to poor density on edges of image on film, take a piece of lino film and see if you get same results.

[bimmridder]

I don't want to get in to a "who's supplies and equipment are best", but here is what we are able to consistently do.

We do a little 4 color process work. We use Kiwo Poly Plus S on 355-31 mesh. It is imaged and exposed on an M&R STE 2 head machine. We run 65 LPI and can hold (not saying print, but hold) a 2% dot. This what what all the components of our system allow us to do. So I can get a 2% dot. Pfffftttt. Doesn't mean the world to me right now. To me, the CTS is nothing new, but integrating the lightbar into the machine is big, making my entire SYSTEM more efficient.

(If I ever make time, I want to play with 75LPI, just for fun)

[alan802]

Update:

 But my problem is I'm getting overexposure symptoms on the small stuff like our regi marks and art info we put on our film.

Alan do the reg marks wash out OK with pressure washer ? I see some of the same issue with HVP but a quick power wash opens everything right up for me.. I am relating this issue it to poor density on edges of image on film, take a piece of lino film and see if you get same results.

We use the pressure washer for everything, it takes some work getting the fine lines and halftones out without wiping them out in the process.

Another couple of wrenches in my plans, the Chromablue emulsion reclaims like a freaking BOSS (Yeah, I said boss cause it's the cool word of the year among the cool kids).  The other problem I have with settling in on a specific emulsion is that the Blue is working MUCH better for detail and even holding the line on the slime test at shorter burn times.  I haven't had any big jobs to test yet to see if we have breakdown at the edges but that's one of my biggest concerns.  The little bit of slime I'm getting doesn't seem to be causing any drip down problems that you can have in your open stencil and if I can get through this 500 piece job we got scheduled this afternoon without any breakdown I'm not sure what the hell I'm going to do.  I shot a 120/54 at 24 seconds and had essentially the same amount of slime as the 60 second screens and I'm going to put a 150/48 through at 15 seconds and see what happens, and that's the 500 piecer...I'll be in touch with results.  As the press turns.

[alan802]

I don't think we've ever really gotten a 2% dot on anything above a 40lpi but I could be off.  I have only recently gotten involved in the lpi outputs our artists were doing and trusted our old artist to do what he felt best.  I have the  OYO test film here I might just throw in on a 305 and see what I can get, but I doubt it will be close to 2% at any of the lpi settings it has. 

[T Shirt Farmer]

...AND WHY DO YOU NEED A 2% DOT??

[ebscreen]

We don't need a 2% dot, ever.

But if you're the rep for a company and you claim your machine can do it, at 85 lpi, I'd like to see it.

[GraphicDisorder]

...AND WHY DO YOU NEED A 2% DOT??

I don't think we've ever really gotten a 2% dot on anything above a 40lpi but I could be off.  I have only recently gotten involved in the lpi outputs our artists were doing and trusted our old artist to do what he felt best.  I have the  OYO test film here I might just throw in on a 305 and see what I can get, but I doubt it will be close to 2% at any of the lpi settings it has. 

[T Shirt Farmer]

We don't need a 2% dot, ever.

But if you're the rep for a company and you claim your machine can do it, at 85 lpi, I'd like to see it.

WORD

[bimmridder]

Well I said I can hold one. Didn't even say I could print it. I think my comment about getting a @5 dot was something like "Pfffftttt", which meant big effing deal. The whole point of my post was the big reason I went LED was it made my SYSTEM better. Just trying to offer a different perspective, but obviously I missed. (slinking back into my hole now)

[alan802]

I think I need to get some perspective on what exactly is a 2% dot.  I wonder if we're all on the same page as to what is a 2% dot, 98% dot, 65lpi, 85lpi, etc? 

[T Shirt Farmer]

We don't need a 2% dot, ever.

But if you're the rep for a company and you claim your machine can do it, at 85 lpi, I'd like to see it.

WORD

IMO if most in this thread worked more on snooping out hidden profits, streamling workflow, training staff to be responsible and instead of 2%-5% or even 7% dots you all would be much better of and many dollars richer.. unless you are a puppet on a BLUE string.. then 2% dots make difference... just sayin