Trapping and Metallic Ink

[Ear]

I know we have talked about this b4 but it has been a long time and I am currently working on a tricky job. And it's a good topic.

I have a perfect bound cover, to be printed 2 up sheetwise on my Speedmaster (4 color press). It also needs a spot metallic and flood varnish on the A side.

My pressman wants to lay the 4c back first, then run Cyan and Spot Gold, for the front side. He will then come back with M, Y, K & Varnish on the third pass. This makes me ponder trapping. Typically, black is the most dense, so everything traps to Black. In this case, the metallic is opaque, which IMO trumps the black. However, since Black will go on after Gold, I don't want to choke the black, only to have it show on top of the gold edge. It has some fine type.

Let's get a little dialog on this. I'd like to hear how you guys do it. I'm thinking about having Gold and Black be 1 to 1 and trap the CMY... if Sierra will allow such a thing.

I'm attaching a screenshot, zoomed in on a couple of characters, un-rendered. The black is a 60-50-50-100 build, which gives me some freedom on trap settings.

[born2print]

I would trap everything, but only .00115", then go home real quick.
and yes, the gold will be more opaque than the black IMO.

[Ear]

  


.... gold more opaque but going down before black. The RIP wants to spread the CMY and trap the gold to black.

I typically see metallic go last, so it covers the trap. I'm not sure if black is opaque enough to cover the gold trap. But I don't want to trap the black to gold, since black will be on top, in case the black is opaque enough to influence the character shapes.

I would love to see black and gold on the same pass, but he isn't going to run that way.

[born2print]

.... gold more opaque but going down before black. The RIP wants to spread the CMY and trap the gold to black.

I typically see metallic go last, so it covers the trap. I'm not sure if black is opaque enough to cover the gold trap. But I don't want to trap the black to gold, since black will be on top, in case the black is opaque enough to influence the character shapes.

I would love to see black and gold on the same pass, but he isn't going to run that way.

Hmmmm, and why is he so set on his run / pass order?

[Fontaholic]

.... gold more opaque but going down before black. The RIP wants to spread the CMY and trap the gold to black.

I typically see metallic go last, so it covers the trap. I'm not sure if black is opaque enough to cover the gold trap. But I don't want to trap the black to gold, since black will be on top, in case the black is opaque enough to influence the character shapes.

I would love to see black and gold on the same pass, but he isn't going to run that way.

Hmmmm, and why is he so set on his run / pass order?

Because he's a press operator... 

Cheers,
John the Fontaholic

[Ear]

He is an old guy and a good pressman. He had a few reasons but I'll ask again tomorrow before I plate it. I think he is concerned about fit and dry trap (CMY on top of the K solid), if he were to lay black and gold on the first pass. I have under-color on the black and he wants black to go down last, just before varnish. 

[StudioMonkey]

I would advise doing the side with the gold first, only because there is likely to be more wasteage on that side (2 passes + tricky trap) - the other side is a standard cmyk single pass.  You don't want to run the easy side first then find you need to run more because of the wasteage on the other side.

Plus, I'm a bit surprised that the gold is opaque.  You must use different inks.  Also I usually have to use a rich black to trap to a metallic but you will know better what might work.

[Farabomb]

We do heavy 4c blacks and gold all the time here. We have the advantage of a 6c press though. The boss used to always freak out, made me do special traps because he heard someone say something about it once. I did once and the pressmen had a hell of a time. Now, it's our normal trap settings with a sequence of metallic/k/c/m/y/varn. The designer loves thin script fonts and black mixtures near 400% and we manage to pull it off. The trapping in prinergy treats the metallic as opaque and I have the sequence set and rarely have issues on press.

Now after it's off there is some offsetting issues, issues with bindery using waste sheets in the live job, not just makeready and not paying attention to flagged sheets but that's a different story. The joke here is red tags mean office copies and green tags mean throw it out.

[andyfest]

We always hit with the metallic first, as it's an opaque ink - then lay down the CMYK inks as they are transparent and usually ghost out when they trap to the metallic ink. To prevent marking, we usually run the metallic as a UV ink and hit it with a lamp before laying down the process colours and Aq coat.

[Tracy]

Veerrry Interesting
Are you guys saying the Black doesn't cover the gold if it runs together?
and it should be laid down first?
Not sure how we did it, but I do remember he did 2 passes

Had a job recently and I didn't see the finished product.
4 color Black and Gold, the gold was trapping to the black

[Ear]

Some great replies here. Good food for thought.

[mattbeals]

we always ran the metallic side first, kcmy (90/40/40/60)-Gold and had the traps spread under the gold.

[Skryber]

When we've had jobs like this, we'd cut the trap to almost nothing. And like Born said, run for cover.

[Ear]

   I cut the trap way down and changed it to "center", to split the difference.

I just looked at the rendered file and now the black text on back is trying to overprint a gold gradient, instead of knocking out. It is outlined, so maybe that is the problem. Text next to it KOs but not the outlined "text". I have tried a couple methods for forcing it but it doesn't want to KO.

edit: I got it to KO. Off to plate.

... then I get to argue with the pressman about ink order.

[Farabomb]

Here are some examples. This book was done in 2 passes. The first laid down the metallic (spot/K/C/M/Y) and process, then another pass for the understrike varn/AQ to get the matte and gloss varnish effect. The black breakdown is north of 320%. Short loads and lots of time between backing up. Sorry about the glare.

https://dl.dropboxusercontent.com/u/40594243/File%20transfer/Archive.zip