Spot Color Mess!

Run straight pMS 021; Problem solved.

D

that's basically what PMS 1505 is, but it's a 50/50 mix of 021 & trans white.
could the trans white be causing the problem? it's been so long since i've mixed inks, could there be a different type of trans white that might work better? That might be a good place to start....
 
Alith7

I do hope that you use Print Control Strip ? problems with Wet on Wet Ink (Trapping) and many others woulld be apparent for ALL to see.


Regards, Alois
 
Alith7

I do hope that you use Print Control Strip ? problems with Wet on Wet Ink (Trapping) and many others woulld be apparent for ALL to see.


Regards, Alois

I had the impression that there was no overprint.
Be interesting to learn the outcome. I say we start a pool. I say it's a pressure problem on the unit. However I will fudge by saying if the sheet has already retained too much dampner (water/ink) (ie wrong ink lay order) bets are off. I doubt this is the case.
Yeah, you could run a solid mixed Pantone to simulate the screen tint, but that doesn't solve anything. It puts a bandage on it.

Anyways; I reckon the operator is about ready to quit about now. That could solve the problem.

I'm thinking I just might put a burger on the grill.

Keith
 
I had the impression that there was no overprint.
Be interesting to learn the outcome. I say we start a pool. I say it's a pressure problem on the unit. However I will fudge by saying if the sheet has already retained too much dampner (water/ink) (ie wrong ink lay order) bets are off. I doubt this is the case.
Yeah, you could run a solid mixed Pantone to simulate the screen tint, but that doesn't solve anything. It puts a bandage on it.

Anyways; I reckon the operator is about ready to quit about now. That could solve the problem.

I'm thinking I just might put a burger on the grill.

Keith

Should I pass around a few bottles of beer while we wait for the outcome? LOL

to summarize, here are the current theories and my responses to them. place your bets accordingly. ;)
  1. Different Ink Formula
    1. Waiting on info from the ink vendor.
    2. Gordo so helpfully provided the photos of what exactly different ink formula's can do. His photo of "regular" PMS mix looks VERY much like what I'm seeing. basically, no dot, just a big smear.
    3. This is my personal favorite answer so far.
    4. I should also add that we frequently print 5-color for a certain customer that uses PMS 350 green. We run 200 line screen, with green in the last unit and have no problems holding the screens open at all.
  2. Wrong (too much?) pressure
    1. a good possibility, although my pressmen assure me that they backed off the pressure as much as they could.
    2. there was also discussion about "answers" from pressmen back there some where.
  3. Running 021 instead of 1505 so you can back off the density:
    1. probably wouldn't solve the issue, we ran the density down so far we almost couldn't sheet any more ink out of the rollers and it was STILL plugged up, no improvement on the screen.
  4. problems with trap (4-color to PMS)
    1. the 1505 was wet trapping to yellow, since yellow was being used to "fill in" the white of the screened 1505. However, we also turned off all units except 1505, and there was no improvement either. BUT we're still in the 5th head at this point.
    2. yes, of course we have a color bar, however this was a tight fit, so I couldn't put anything extra on, and the closed loop system that we have unfortunately does not allow me to customize the color bar. Sadly, Ryobi's required color bar pretty much only measures density. it's ridiculous, especially since it's the Techkon scanner, and Techkon software allows for a fully customized color bar (we had it on our old Heidelberg). I've argued with Ryobi continually, and they will NOT budge. Short of it comes down to can't measure trap.
  5. Wrong lay-down order
    1. that -might- still be the issue. order was Black -> Cyan -> Magenta -> Yellow -> 1505. This might also point to a trap issue due to an over saturated sheet.

So, that is where we stand with possible solutions right now.

Gordo, if you're still lurking around here, I have a couple questions about your photos. What PMS color was that you were testing? I find it interesting that your examples are orange, and orange is what i'm having problems with. If it is an ink issue, is it an issue that's more prominent in certain pigment families?


Also, thank you everyone for joining in on this LONG debate.
;)
 
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Alith7,


Why are you not printing 4 colours KCMY (FOGRA) In the UK when we order Spot Colours/PMS for Coated/Uncoated. The Ink as to

print Solids/ Halftones/ Text .......... whatever image is on the plate.


Regards, Alois
 
"My response was simply an enthusiastic thank you for his help in persuading people on my end. So why were either of these comments necessary?"

My apologies Alith7. Should have realized you were simply being polite to all that provided input. I'll crawl back into my hole.
 
"My response was simply an enthusiastic thank you for his help in persuading people on my end. So why were either of these comments necessary?"

My apologies Alith7. Should have realized you were simply being polite to all that provided input. I'll crawl back into my hole.

Have a beer and join the fun. ;) A few years ago I poked at the to linearize or not to linearize debate... I don't even remember how many pages that one went. And NO to anyone who was thinking about it, do NOT start that one here.....
 
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Alith7,


Why are you not printing 4 colours KCMY (FOGRA) In the UK when we order Spot Colours/PMS for Coated/Uncoated. The Ink as to

print Solids/ Halftones/ Text .......... whatever image is on the plate.


Regards, Alois

Because we ARE printing KCMY.... Please excuse my brain fart. I will edit my "summary" post accordingly. :eek:

oops, was soo embarrassed I missed the second part of your question. I don't believe we have ever ordered PMS for coated/uncoated. We do order special mix for UV coat, and extra driers and such for difficult stock like poly, or metallic. and depending on this outcome, maybe by solid/halftone after this.
 
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If I read your post correctly, the pressman is running the colors out or order. I have intentionally tried to run CMYK in different orders just to see what the out come would be. IT"S TERRIBLE. No matter who the manufacturer of your ink is, they all make the ink to lay down K,C,M,Y on the first 4 units. I assume you are printing the 5th color on the 5th unit. I have a question. Does each ink unit have a separate water unit? If so it is a good possibility that the water solution they are using is contaminated. If it is contaminated, drian the system and clean it with like this and it should be clean. Mix 16oz. of Ammonia with 4 gallons of HOT water and put it into the water unit and circulate for and hour, then drain and run 20 gallons of water through the system to make sure all the ammonia is out. If not, is the ink used to run CMYK from the same manufacturer as the spot color? If not then you probably have a resin problem trapping with the CMYK. The only way to prevent that is to run the CYMK separately and then come back and run the spot because the CYMK should be dry by then. The only other thing I could tell you is to replace all the packing and blanket on unit 5 and do a test just run. It could be the blanket has lost it's elasticity therefore ink will not adhere to the rubber properly.
 
Gordo, if you're still lurking around here, I have a couple questions about your photos. What PMS color was that you were testing? I find it interesting that your examples are orange, and orange is what i'm having problems with. If it is an ink issue, is it an issue that's more prominent in certain pigment families?

It was PMS 172

Quoting a commandment from the Ancient Ink Sequence Masters: "The ink sequence shall be Dark to Light, Opaque to Transparent - unless there's a specific mechanical reason not to." One example of a mechanical exception is newspaper work where Y may go down first and K go down last (Y typically makes up the majority ink usage in a traditional separation so going down first helps seal the paper giving a better result for the following inks. The K ink is typically crappy ink and if put down first might contaminate the following inks)

Alith7, you actually have an indirect relative ink film thickness gauge - your densitometer. Measure the SID of the PMS ink in your swatchbook and do the same for the SID of that PMS ink on your presswork. They should be within +/- 0.10 of each other and that should indicate an ink film thickness of about 1.5 microns.
 
I'm going to go with John Seymour on this one

'There is nothing magical about density that allows it to put a micrometer on an ink film'
 
With that said, 'There is nothing magical about density that allows it to put a micrometer on an ink film', pigment amount or colour strength is directly related to the density that is produced.

D
 

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