Trapping

[bejamshi]

Do you do much trapping of colors before sending out your files to printers.
Some printers say their programs already takes care of it, is this true with
all printers?

Thanks

[morea]

ask the printer what they want before you submit the files.

[jimking]

Any printer worth his salt will trap the job and insist on it. If you run across a printer who wants you to trap, find another printer. So, ask first.

[Virgo Nightingale]

Your printer should take care of trapping for you. The only time I ever worry about it is if I'm using spot colors and I need a particular element to overprint or knockout what's beneath it. Other than that, I let the printer worry about it. They know their own press better than I do (or at least they should) and they will know the best settings for it.

[bejamshi]

Thanks my friends.
My printer just told me they do all the work.

[jimking]

Your printer should take care of trapping for you. The only time I ever worry about it is if I'm using spot colors and I need a particular element to overprint or knockout what's beneath it. Other than that, I let the printer worry about it. They know their own press better than I do (or at least they should) and they will know the best settings for it.
I would definitely tell the printer what to overprint other than black. If you set a particular spot to overprint, the printer may K/O and trap even if it's set to overprint because half the time Illy, Quark, Indy etc. documents have elements set to overprint including white and we change these settings everyday.

[Virgo Nightingale]

I do tell them... but those are the only instances where I bother with the trapping in the first place.

[CamarotaDesign]

Yeah, most printers do it automatically, but some have poor registration on the press. And you usually have to trap rich black yourself. (100k + cmy) The way I do a manual trap is by setting up an overprint strokes. Even if they have trapping software, registration can be difficult. Overprinting strokes makes it very easy for the press operators to register color on top of other colors.

[jimking]

One of the main concerns with adding an overprint stroke around text is if it's a serif or thin a font, causing it to plug up on press. Our trapping software deals with reversed out white objects out of rich blacks very well. What it does is it spreads cmy underneath the black while the black retains its original shape. This allows cmy to bounce around underneath the black without these colors popping into the white area in the rich black. We can also change the numbers to suit different presses. Not all rips are able to do this however.

[budafist]

Our RIP does the trapping for us. So, as a prepress person at the printers, even I don't have to do any trapping. :)

[jimking]

True, trapping has become pretty much done on the fly. But when it pertains to metallic inks that's when I'll step in and change the settings. Metallics lay on paper differently, they spread much more. Trapping needs to be cut back in most cases and treated as the dominate color not black as far as which color to spread into.

[budafist]

We tinker with the trapping only after the printers can't get it to fit. It doesn't happen very often thank goodness - maybe once every 2 months. If it did happen more often then we'd have to figure out a system to save on plates. I wouldn't know enough about it to play with it before seeing how it prints :(

[Ned]

I don't need to trap my designs. They come right to me.

[budafist]

Speaking of traps... (http://johncarmichaels.typepad.com/carmichaels_position/WindowsLiveWriter/TheSoldiersTrapInsurgencyGetsInnovative_D227/military_trap_thumb.jpg)

[jimking]

That's called a trap and rip.........apart. :)