Layer setup in CMYK

[Reber]

Oh, and yeah the method I gave does not include trapping. As Dave pointed out. I currently do that after. As my method for coloring the lineart or painting, or screening over the lineart, works best with the lineart untrapped.

I don't understand that part. How does what you do underneath the lineart effecting what you do above it? You should do a tut on how to convert an RGB image and trap.

[Sweeney]

I don't understand that part. How does what you do underneath the lineart effecting what you do above it? You should do a tut on how to convert an RGB image and trap.

You can't trap in RGB - black is 0R 0G 0G. Anything you put under it will still be solid black (0R 0G 0B) if you flatten the image before converting to RGB, and the black will convert to a mixture of CMYK.



I helped Ted with some trapping with glows and FX last night. It's a real long-winded explanation, but I'll try to post a Tut on it next week.

[Zombie Dave McCaig]

this thread is how to paint in CMYK though!

If anyone wants to post a separate one to help RGB folks, that would be great.

[Reber]

I know you can't trap in RGB... doesn't hurt to have a trap layer to go when you convert to cmyk. You just backfill the layer with the appropriate color. I want to know how doing something on a layer underneath the lineart which shouldn't even be visible.. effects how he does effects above it.

[Josh]

Right on, y'all.

[MBirkhofer]

No, I was saying the things I do above or on the lineart, effect the trapping.

And to be fair, my first post was in a differant thread...

[MBirkhofer]

Actually, my final layout is a layer with the trap with the 60C40Y40M100K black set to normal(Or whatever %cymk is asked for). Below is the untrapped lineart with 100%k, set to multiply. Then the colorlayer. To get screen layers to work, the areas screened and lineart that is painted over, or screened over needs to be flattened into the color layer, before the CYMK conversion.

I'm not really sure what the formula for multiply or darken are, compared to each other.

Again, my methods I stumbled across myself, and from things I picked up on. I don't work professionally, so I could be off on something. I know its really not the fastest method...

Josh, There are alot of ways to do anything in photoshop. Becoming famillair with all the fuctions takes awhile, but is a large part of learning to color digitally.

[Seed]

now i am really confused.

Mb because of the fact English is not my native language...
sorry this may sound stupid....but i didn't get this.
What is the "trapped" layer for ? And how does the "hold" layer work?

o.O
it's 1:41 am mb that's another reason -- --
I simply seperate the line art on an own layer. If i want to change the line art, i check "preserve transperancy" (i think that's what it is called in english)...or hit Control+click and simply paint over the lines o.O
But interestin to see how u handle it.

Bye
Seed

[Zombie Dave McCaig]

...And lock the transparency of the top layer. Your lineart is now on it's own layer and locked.

Multiply does not work for print. As it allows the undercolor to show through completely.

Actually, my final layout is a layer with the trap with the 60C40Y40M100K black set to normal(Or whatever %cymk is asked for). Below is the untrapped lineart with 100%k, set to multiply. Then the colorlayer.

I'm not really sure what the formula for multiply or darken are, compared to each other.

Ok, MBirkhofer... I'm not sure which of these statements you meant...you kind of contradict yourself, as I understand it. Also, it sounds like you put the trap on top of the lines? I never though of doing that...hmmm

Anyway, You can use multiply or darken for the lines layer as long as you are using truly aliased artwork. It will function in the same way, although only with 100% values, such as the 100%k line color. If the art is antiliased, I'd recommend multiply, or you'll get color clipping. (As in when coloring pencilled artwork as opposed to inked)

For regular aliased art, I set my layer to darken. I like the way it previews, and I suspect it renders faster, but I'm not certain...

**In CMYK**
Darken works like this: say you have a green that's 50%c50%y on a darken layer. This will apply the numeric values of those 2 channels (c&y) onto the layers below, affecting any color up to 50%c and 50%y, but on higher values it will leave the areas unaffected. Other channels will also be unaffected.
Meaning over a color like 20%c80%y30%k, 50%c50%y will change the color to 50%c80%y30%k Make sense?

multiply works like this: with that same green (50%c50%y) set on a multiply layer, it will affect the layer below by basically adding it's numeric values, but not at 100% strength. PS uses some messed up algorithm to do this, but I don't know what it is, and I honestly don't feel like figuring it out right now. I do know that it works on a diminishing curve.

At any rate, multiplying 50%c50%y onto 20%c80%y30%k results in 60%c90%y30%k. This shows that the multiply function affects lower numeric values more than higher ones.

I hope this is more helpful than confusing.

[Zombie Dave McCaig]

What is the "trapped" layer for ?

Color printing uses transparent inks. The black is also transparent...this means that if you have a bright yellow shape and a dark purple shape below an area of black lineart, it will print with a really obvious color shift, even though on screen it would appear to be truly black.
To get around this, people do one of two things:
1) They just make the lineart layer some mixed black color.

Maybe the default PS black, and set it on normal mode.

The problem with this is that if the colors print off register on the page, any fine feathering will get muddy due to the colors on each plate fanning out. This looks pretty bad.

2)They set up their page more or less like I demonstrated.

This way, if the plates shift, there is room for error, as the black lines with mask any small shifts. Also, the trap color fills in those problem color areas I mentioned earlier.

I think someone may have made a demo of this and posted it on CC a long time ago... maybe they still have it and could post it...

And how does the "hold" layer work?

I suggest you build a file using my method in the first post of this thread and try it out. It makes more sense when you see it in action.
There are tons of other ways to do color holds, as well... maybe other people will post their methods....

[Seed]

ya know i never made anythin with masks and stuff


Seed

[Zombie Dave McCaig]

just load a selection, make a new layer, and hit the button in the layers palette that looks like a circle with the broken lines around it. Then make sure you go back to your main color channels and voila!

[Brian Boyko]

Bookmarked!

[WhoIsRico]

Just wanted to bump this oldie but goodie up. I was referring to it for some trapping info. Thanks Dave!
-rico

[Cantina-Dan]

So do you go back and do all of the trapping once you've finished coloring a job?

Is this how you do your trap?:
1) Load the selection of your line layer
2) Create a new layer
3) Contract your selection a couple pixels
4) Fill with a predetermined trap color
5) Set layer to multiply or darken