Before You Went LED, What Were You Using?

[jvanick]

This is a huge reason why I was asking before about UV light wavelengths and emulsion sensitivity.

We as the consumers, are VERY much in the dark about the true science behind why things are working/not working.

the emulsion manufacturers won't tell us
the equipment manufacturers are very tight lipped too...

until we get both pieces answered, and not just "call us and we'll tell you if you ask" and put in a chart somewhere, we can't make educated decisions.

Heck, even if the emulsion manufacturers gave us a chart that said "this emulsion works best with this LED unit", that might be a good start...  but honestly, I'd like to make that decision.

First emulsion manufacturer that starts that kind of testing and information, along with the typical viscosity, solids %, etc, will likely get our business... I HATE secrets like this that cause US to have to do so much testing/experimenting/etc...

[244]

This is a huge reason why I was asking before about UV light wavelengths and emulsion sensitivity.

We as the consumers, are VERY much in the dark about the true science behind why things are working/not working.

the emulsion manufacturers won't tell us
the equipment manufacturers are very tight lipped too...

until we get both pieces answered, and not just "call us and we'll tell you if you ask" and put in a chart somewhere, we can't make educated decisions.

Heck, even if the emulsion manufacturers gave us a chart that said "this emulsion works best with this LED unit", that might be a good start...  but honestly, I'd like to make that decision.

First emulsion manufacturer that starts that kind of testing and information, along with the typical viscosity, solids %, etc, will likely get our business... I HATE secrets like this that cause US to have to do so much testing/experimenting/etc...

Here is where the problem lies. Manufacturers like M&R who do the research and then freely give the information either on forums or even to end users end up being the research and development people for all the other manufacturers for free. Then our product is more costly due to the research cost the others don't have. As most people look at cost first that put you at a disadvantage immediately. The Starlight is a perfect example. We have more cost in our LED bank than some have as a retail price for their retail unit. Our vacuum is quiet and pulls down in 15 seconds. Guess what? That has a cost. We won't reveal why ours works better so we rely on end users to tell others. I also encourage end users to tell good or bad .If there is no bad and people think that is being withheld that ends up being their loss. We do a tremendous amount of testing,so much I can't even imagine the amount of screen meshes, emulsions, coats, and squeegee strokes with various inks. We even hired Lon Winters as an outside consultant for two solid weeks to coat screens, image, and test. I seriously doubt any other manufacturer has done these type of test to this degree. Can't give that away for free to the competition and that is why it's not all posted.

[ebscreen]

This is a huge reason why I was asking before about UV light wavelengths and emulsion sensitivity.

We as the consumers, are VERY much in the dark about the true science behind why things are working/not working.

the emulsion manufacturers won't tell us
the equipment manufacturers are very tight lipped too...

until we get both pieces answered, and not just "call us and we'll tell you if you ask" and put in a chart somewhere, we can't make educated decisions.

Heck, even if the emulsion manufacturers gave us a chart that said "this emulsion works best with this LED unit", that might be a good start...  but honestly, I'd like to make that decision.

First emulsion manufacturer that starts that kind of testing and information, along with the typical viscosity, solids %, etc, will likely get our business... I HATE secrets like this that cause US to have to do so much testing/experimenting/etc...

Here is where the problem lies. Manufacturers like M&R who do the research and then freely give the information either on forums or even to end users end up being the research and development people for all the other manufacturers for free. Then our product is more costly due to the research cost the others don't have. As most people look at cost first that put you at a disadvantage immediately. The Starlight is a perfect example. We have more cost in our LED bank than some have as a retail price for their retail unit. Our vacuum is quiet and pulls down in 15 seconds. Guess what? That has a cost. We won't reveal why ours works better so we rely on end users to tell others. I also encourage end users to tell good or bad .If there is no bad and people think that is being withheld that ends up being their loss. We do a tremendous amount of testing,so much I can't even imagine the amount of screen meshes, emulsions, coats, and squeegee strokes with various inks. We even hired Lon Winters as an outside consultant for two solid weeks to coat screens, image, and test. I seriously doubt any other manufacturer has done these type of test to this degree. Can't give that away for free to the competition and that is why it's not all posted.

How about EOM measurements pre/post exposure with MH/LED as discussed earlier in the thread? Or magnified photographs even? I don't think either
would give anything away to your competition other than bragging rights.

[jvanick]

Let's get this back on track:

How about EOM measurements pre/post exposure with MH/LED as discussed earlier in the thread? Or magnified photographs even? I don't think either
would give anything away to your competition other than bragging rights.

funny that you post this... as part of my emulsion issues, I JUST ran that same test about 15 minutes ago.

screen was underexposed as far as the stouffer strip is concerned (I talked to Al at Murakami and found out that we have bad diazo)... so I'll re-run this test when we have better screens...

but... with 4-5 solid steps on the stouffer strip:

EOM measurements matched both pre-exposure and post-exposure with no change ... (55 microns mesh, 82 microns mesh+emulsion) 

not so sure that EOM is a good indicator of poor exposure or not.

[ebscreen]

not so sure that EOM is a good indicator of poor exposure or not.

I was wondering if it would be a viable test. Indications to the negative are as good as to the positive for me.
I'd wager emulsion mfgrs probably know what a good indicator would be? Shade tree is wiping a white shirt on the back
of the screen post development.

[Dottonedan]

There have been a lot of posts pertaining to LED and how much everyone loves theirs and I was wondering what the perspective is since one's opinions on them is mainly shaped by what they were using before. 

I'll start, we were using a Richmond Solarbeam with a "10K" bulb and I put that in "" due to the fact that I've had a few guys tell me it's not close to actually being a 10K and more like a 6-7K output.  I've said many times that I thought this expo unit was one of the best ever made and even now after using LED for a few months I feel even more solid about that.  I can understand the opinions of the LED's being so high, especially if you were burning screens with flouro bulb units or lower powered metal halide units, but I'm really wondering if anyone has come from a 5K and up metal halide to an LED unit that thinks the LED is significantly better or even on par with the MH unit.  There are still more pros for our LED than the MH but fully crosslinking the emulsion and getting full exposures is not one of them.  Our MH unit outperforms the LED by a big margin when it comes to the most important part of the equation...burning the image completely through the layer of emulsion.

Has anyone come from a 5K Olec or one of the stronger Trilight units from M&R to an LED?  I'm just looking for some perspective on how LED opinions have been formed.  So if those of you who have gone LED could share what you were using previously and have time to compare/contrast the two I think it would be appreciated.  I'm not knocking LED because even with my issues I think it's a better option than MH right now but in my opinion it's not superior in some ways that it's being assumed to be.  It deserves praise but I think that we need to tap the brakes a little bit and put things in proper perspective so others who haven't pulled the trigger can get the whole story and one that isn't biased in any way.

Lets bring the topic back on track, going back to the original post.

I still like and think a MH is a good product/device. If I were given one (Alan, if you want to ship me yours), I'll take it.
I assume Alan has an EOM metor. He's pretty well known for knowing his screens, coating, mesh and emulsions so it would go hand in hand that he would have one of these. So let me ask, what is a typical eom on a 280, 230, and a 110?  You probably have an average where you like to be.

I'm looking at (why) even with the MH, one would need, or choose to cut back on exposure time (intending to hold smaller dots) than normal exposures of non halftone work.

For me, this says that the EOM may be thick. Now, thats not a bad thing. Some shops as we know, intend and prefer a thicker emulsion. Where I'm going with this, is that (maybe), just maybe, and I'm guessing here and speaking for myself not knowing details, that a MH could be as strong or stronger than some LED.  The reason being, (here's the guessing part) is that maybe a MH is more (or as) intense for longer periods of time. This possibly signifies why even with a MH, one would cut back on exposure time to hold more dots...

Normally, I would say this would be due to possibly a thicker emulsion layer than normal or what is a (standard, typical or average) EOM layer.  I can understand the need or procedure and yes, have heard of people purposely doing underexposure for many years More so, I beleive it to be an older or maybe old school technique. With that, I would imagine that the desire for thicker layers of emulsion is more geared towards high wall printing or sharp edge where the ink is laid down thick enough for a 1 hit on an underbase. For halftone purposes or as it pertains to halftones, doing underexposure to obtain small dots (to me), was considered a work around or a band aid to other issues. A typical thicker layer is one good thing. Thicker or rather excessively thicker layers, and halftones don't work well together.

If a thicker than normal layer of emulsion, is indeed the case, then I can understand some thicker layers of EOM needing exposure time adjustments to cook it all the way thru. If you are not accommodating the thick emulsions and holding halftones due to under expsoure, then you are deteriorating the back of the emulsion while holding halftones. I don't think the two (really thick layers as well as fine halftones) can live together on the same screen (UNLESS, your halftones can take it or in other words, unless you use a much lower LPI.

For an an example in the extreme direction, take cap film at 400 micron on a 110  mesh.  That is not going to hold 22 lpi well in the lower end dots. A 22lpi would be a good lpi to use on a 110 mesh (intending to hold the small dots) on that mesh. YOU CAN, hold more dots...by decreasing exposure,...but the back is not going to provide as good of an image due to it not being exposed long enough for the stencil to fully cross link and cook (that thick). It's a tight battle. Now again, this is an example in the extreme direction. The low LPI helps to achieve this on the 110 alone, but given that the emulsion layer is sooo thick, it would require a longer exposure time to achieve a great stencil.

So yes, if your exposure times need to be decreased to hold smaller dots, I would assume you have an emulsion layer thickness that is well above the average. Again, in many cases, I would do the same for a desired look on specific type of prints like especially in the case of an athletic print with white ink on red 50/50's.

With halftones, you have a point of diminishing return on the emulsion layer thickness.  This leaves me to consider, is is really a question of MH or LED, or is it a question of techniques and needs?  As it's been mentioned, there was and is a need or preference to cut back on exposure times in both devices, being the MH and the LED device.  The preference comes from the true desire for having a thicker layer of EOM.  From what I remember having been told and read from some good people in the emulsion industry, an average EOM might be in the area of 20% for lower mesh such as 110 up to 230 and 15-10% on high mesh like 305 and 350 mesh. These %'s of EOM suggestions are simply that, suggestions or averages for what has been determined "good" stencil thickness's for various mesh.

Having a EOM meter, can take that guess work out. Those who do not have an auto coater....but want to print fine halftones and repeat the same image at every reorder, should want to get a EOM meter. As we all know, Bob does not coat the same 1:1 sharp as Mary does, nor does Bob do the same coat tomorrow.

Anyone can jump in to correct me on those percentage averages because I'm just going be memory.

Does that make sense?

[Dottonedan]

I know a guy that needed a DTG. He bought one and paid a high price for it. He loved it! He used it for a month and his business changed a little but just enough for him to not need the DTG. It didn't do what he now needs. So, he put it up on line for sale at 30% off the original price. 3 times he lowered the price. No takers. He then stored it for another year or two and tried to sell it again for almost giving it way just to make room. No takers. So he decided to trash it. He loved it at first, but things changed but it was still a good machine that could be useful to someone with a different perception. The product was not a bad product, the need was just not there like it was, and his perception of its value changed. Things change.

Someone listening to that story might think there must have been something bad about the Co that made it less attractive to buyers, or the product was junk. Most often, there is more to the story (the back of the back story) than we hear or are told directly.

I like the analogy of "the big meeting".
It's not what is said in the "big meeting" that people want to hear, it's the smaller meetings after the big meeting that contains the real juice. It may not be accurate, but it's juicy.

[Underbase37]

Ill send him a message about this post, maybe he will chime in and make this interesting.

Hopefully he'd do it in it's own thread in Running and Growing a Business

Yes. That would be nice. It would be great to see this topic get back on track. I had a few things I wanted to add, but was waiting to gather more data before I did. Now I'm not to sure its worth it.

Murphy37

[bimmridder]

Does this have anything to do with the thread? If I coat and dry a screen and then measure the EOM and get "X" microns, then expose and develop it and let it dry, measure again and get "X-4" microns, wouldn't that mean some emulsion went down the drain, thus underexposed? (How's that for a run-on sentence?)

[mk162]

Did anybody else miss in the post how Alan was saying his films aren't as dense as they were before his artist left?

That's huge right there....too low a dmax and you will struggle to cook your emulsion without exposing right through your stencil.

Just sayin.

[Frog]

Does this have anything to do with the thread? If I coat and dry a screen and then measure the EOM and get "X" microns, then expose and develop it and let it dry, measure again and get "X-4" microns, wouldn't that mean some emulsion went down the drain, thus underexposed? (How's that for a run-on sentence?)

That was the premise I proposed, I believe, though I must confess that I have missed some posts here since then. I think that it was in this thread, LOL!

[Underbase37]

Like when I under expose an 83 mesh, lose half the emulsion on the back & the damn image starts to fall away from the screen 1k prints in. This has happened to me both with MH & LED. Under exposed is under exposed, & both are my fault. I don't know if this is what is going on with Alan's problem.  Just saying.

Murphy37

[bimmridder]

Sorry Andy. I wasn't reading all of the posts.

[jvanick]

how underexposed do you have to be, or how aggressively are you rinsing the inside of the screen?

My tests here over the last few days have shown that I can be at least 3 steps underexposed, and the emulsion doesn't get any thinner.

[Frog]

Sorry Andy. I wasn't reading all of the posts.

That is understandable on these long ones, especially when they get a second life, (and a bit of a change of direction)

I figure that remaining EOM has to be at least one measurable indicator of exposure "completeness" though according to jvanick contains some latiitude.