Spot Color Mess!

[Alith7]

I have a question for you guys.

Why would a spot color not be able to hold open a 50% screen?

We have tried at 175 lpi and 200 lpi. Both plug up complete (looks like 100% with a waffle pattern).
Plates are fine, I even tweaked the file to open it up to a 40% screen and they still can't keep it open?
Printing on 100# Gloss Cover, PMS 1505.

I would think it's something wrong with the press or operator error or something, but they keep insisting that the file is bad. I don't see how this could be.

Any input would be a help! I managed to fudge the file enough for the customer to be happy so we could runt he job, but i'd still like to figure out what the %)#($ is going on.

Thank you!

 

[Alith7]

oh, and the pressmen are telling me that they have the water full open. Could too much water cause this problem?

 

[gordo]

It is quite probably the ink. You need to always tell your ink supplier when the spot color ink will be screened and/or wet trapped with other inks so that the ink is correctly formulated for that use. I've seen the problem you're describing very often in hi-fi/extended gamut printing when the printer simply asks for a PMS ink without saying how it will be used.

 

[Alith7]

see photo. (found a fun trick with taking pictures through the loop with my phone.)

This is a close up of the 40% screen area. While it is not 100% clear, the "dot" is not blurred out from the photo. there is NO DOT.
Too much water?

This is a 5-color job, but the only other color in this area is yellow. Customer wanted to fill in the "white" areas of the screened PMS with yellow. And you are probably right, I think they just mixed this PMS with our standard mixing bases. I didn't know that there were different formulations of the ink depending on use. although it makes sense. I will discuss that with them.

The press is a 4-year old Ryobi 755. Normally it prints beautifully. The other thought i had was that ink order might be a problem? this was run Black -> Cyan -> Magenta -> Yellow -> PMS 1505.

Thank you Gordo! you are always full of great info!

 

[Cornishpastythighs]

Do your press guys usually have to run their water settings at 100% on their regular process inks? Most certainly too much ink and too much water could result in mushy waterlogged dots.
Maybe the ink is too weak and they have to carry a lot to achieve required density resulting in carrying a lot extra water to keep the non image open. I would have them check out the print unit for correct roller/dampening settings, also check out the fountain solution dosage is at spec. After doing this and eliminating your equipment I would have the ink manufacturer work on the ink.
Water buildup on the print units prior to the colour can sometimes have a negative effect on how the ink lays down.

 

[gordo]

I agree with Cornishpastythighs however I would start with your ink vendor rather than end with them. Also buy a USB microscope - less than $75 and is an immense help in identifying and documenting issues as well as what dots should look like when correctly laid down.

 

[Alith7]

No, they don't normally run at 100% water, which is why I was thinking that might be one of the problems. As far as saturated paper from the previous units, putting down the PMS last might also be a contributing factor.

I think the wrong ink type is probably a part of it also. I'm going to talk with the ink vendor and see what they say. I did confirm that they just used our regular mixing base to make the PMS, so there was nothing "special" for the application.

I have a Beta Ind. "Color Viewer III" with 50x magnifier. it's not digital, but it usually works great for me to see what's going on. The pressmen have zero interest in looking at the dot to see what's going on. So having the ability to pull up a digital image on screen will help no one anyways. This whole thing started this morning with me walking in back for something else and the pressman stopping me with "they're going to hate this" in reference to the what the customer was going to say when they got here for the press check in about 30 mins. Not "something isn't right" or "we need to take a look at what is going wrong here". SO not helpful. And when I took a look and said that the 60% screen was completely filled in and there was something going on with the press all I got was a blank stare. The usual "it can't be the press, something's wrong with the files" attitude. And so i'm here, trying to get some ammo to throw back at them to get this figured out. The job is done and off press, but I want to know what is going on so I don't have to have this battle next time.

One of the things they threw at me trying to blame prepress was that it must be the wrong "curves" for spot colors. I couldn't get them to understand that a "curve" isn't going to make a 20-30% shift. And that if they can't even get a 60% screen to stay open at ALL then there was something going on back in the press room. It doesn't help when the owner backs the pressmen and tells them I'm wrong.

 

[Cornishpastythighs]

Yes been embarrassed too many times by pressmen who assured me that the press was not the problem but the ink and then have some ink tech come in and find a problem with the press. I always check the press out first then I can confidently say the issue is not the equipment.

 

[Alois Senefelder]

I despair......... yet again.


Alith,

Thank you for the picture of "Sunspots" please post a picture of the said "Image" on the plate.

Next the "answers" you are getting back from the printers........ tell me - that they are sadly lacking in the knowledge

of printing by "Lithography"


Regards, Alois

 

[QualityPrint]

Have the pressman take the spot color plate and put it on a unit with black, cyan, magenta or yellow and see what you get after you run it up. If the screen plugs then it points toward the plate. If the screen is nice and open then it points toward the ink or some other part of the press.

 

[Alith7]

I despair......... yet again.


Alith,

Thank you for the picture of "Sunspots" please post a picture of the said "Image" on the plate.

Next the "answers" you are getting back from the printers........ tell me - that they are sadly lacking in the knowledge

of printing by "Lithography"


Regards, Alois

I hope not despairing over me!
Over my pressmen, go right ahead. It's sad that one of them always brags of his 25+ years experience running press (actually, he was just mouthing off this morning about it) and I know more about ink, color theory, etc. than he does. As the Prepress manager, I feel that I should NOT be having to tell the pressmen what to do to print a job correctly, or that I should not be the only one trying to tackle this problem. but maybe that's just me......

I know that the "answers" I'm getting back are half lazy, and half "I don't care". Either way, yes, I know the supposed answers are BS.

And my "sunspots" are sadly not a bad photo even though it may seem that way. That is ACTUALLY what the print looks like: One giant smear.
I can't get a picture of the plate at the moment, but I can give you a screen shot of the TIF file that was burned to the plate. you can see a scale on the left for reference. it's in Inches. Does that help?

 

[gordo]

[snip]
I have a Beta Ind. "Color Viewer III" with 50x magnifier. it's not digital, but it usually works great for me to see what's going on. The pressmen have zero interest in looking at the dot to see what's going on. So having the ability to pull up a digital image on screen will help no one anyways. This whole thing started this morning with me walking in back for something else and the pressman stopping me with "they're going to hate this" in reference to the what the customer was going to say when they got here for the press check in about 30 mins. Not "something isn't right" or "we need to take a look at what is going wrong here". SO not helpful. And when I took a look and said that the 60% screen was completely filled in and there was something going on with the press all I got was a blank stare. The usual "it can't be the press, something's wrong with the files" attitude. And so i'm here, trying to get some ammo to throw back at them to get this figured out. The job is done and off press, but I want to know what is going on so I don't have to have this battle next time.

One of the things they threw at me trying to blame prepress was that it must be the wrong "curves" for spot colors. I couldn't get them to understand that a "curve" isn't going to make a 20-30% shift. And that if they can't even get a 60% screen to stay open at ALL then there was something going on back in the press room. It doesn't help when the owner backs the pressmen and tells them I'm wrong.

Your experience with press operators is different than mine - maybe because I'm often an outsider so I get some respect that a co-worker may not. The thing about the USB scope is that you can take photos that you can share with others to get help. I have found that press operators can be quite interested in seeing the dots they print this way - especially if you have images of dots that are properly printed to compare with dots of concern.

 

[Alith7]

Have the pressman take the spot color plate and put it on a unit with black, cyan, magenta or yellow and see what you get after you run it up. If the screen plugs then it points toward the plate. If the screen is nice and open then it points toward the ink or some other part of the press.

I think they were talking about trying that at the end of the day, but I can already tell you what's it's going to do.... it's going to look just fine.
If it were a plate issue, I would be seeing it on more than one unit, I'd be seeing it on all. Also, we burned 3 different plates as I was trying to make prepress adjustments to compensate, so that eliminates a bad plate.

 

[Alith7]

Your experience with press operators is different than mine - maybe because I'm often an outsider so I get some respect that a co-worker may not. The thing about the USB scope is that you can take photos that you can share with others to get help. I have found that press operators can be quite interested in seeing the dots they print this way - especially if you have images of dots that are properly printed to compare with dots of concern.

I'll look into getting one. I had gotten one before, but it ended up being a Chinese POS and couldn't focus on anything. discouraged me a bit I guess.

and I WISH my operators had an interest in understanding that looking at the dots can usually tell you exactly what is going wrong. But they have the double standard of "you figure it out, it's not a press problem" coupled with "what to do you know about the press, you're wrong, and that's not the problem" when I try to point out what the issue is. They would rather have me continue to bandaid files and monkey-rig every problem from the prepress side so they don't have do anything and can say it was all on my side of things the whole time.

sorry, slightly bitter, frustrated and VERY irritated right now.

 

[gordo]

I'll look into getting one. I had gotten one before, but it ended up being a Chinese POS and couldn't focus on anything. discouraged me a bit I guess.

That's the kind that I use. It may be how you're using it. There may be a clear cap at the front end that you need to take off before using.

 

[Alith7]

That's the kind that I use. It may be how you're using it. There may be a clear cap at the front end that you need to take off before using.

yes.... I'm a girl. I'm not a blonde though.....

I think I got a SUPER cheap one. Like $20. The software didn't work at all.

 

[gordo]

yes.... I'm a girl. I'm not a blonde though.....

I think I got a SUPER cheap one. Like $20. The software didn't work at all.

There's a few guys here who didn't notice that clear cap and were complaining about focus issues. ;-)

 

[Alith7]

I like to think I'm a little more observant than that.... I'm a techy, not a graphics person. case in point: I had a 3-Phase 300lb battery back-up in pieces on my floor last night so I could replace the batteries. Stupid things had swelled just enough that they were wedged in and I had to tear 3/4 of the box apart to get them out. But it is now all reassembled and powering our plate burner beautifully. LOL sorry. completely off topic!

 

[mwc]

Have the pressman take the spot color plate and put it on a unit with black, cyan, magenta or yellow and see what you get after you run it up. If the screen plugs then it points toward the plate. If the screen is nice and open then it points toward the ink or some other part of the press.

Agreed -
From a prepress point, my FIRST finger pointing back to the pressroom would tell them to take the (cleaned or reimaged) plate, put it on one of the proven/printing units - the K,C, or M, don't mess with no 'spinney knobs or doohickeys' and show me some sheets. (standard densities, and assuming a colorbar on the sheets with at least 25,50,75 screens also)
SECOND finger would grab a 10x loupe and see if you 'gotz some sharp dotz'.
If so, My THIRD finger would point to the pressroom...while removing the first and second fingers from the equation (not your issue).

 

[curiosity]

No Title

I got the Chinese POS too, and sometimes it works, but usually after several restarts.
So a short while ago I did a little of what Alith7 did and used my phone's camera with my Beta ColorViewerIII.
This pic is using the 100x adapter. Un-retouched.