Links to multi-channel tutorials???? 1

[mistercitizen]

I've been experimenting with the multi-channel mode of late, and it strikes me as a rather under-utilised color mode. As such, I have not been able to locate any comprehensive tutorials/resources on the mode and the effects (and problems!) possible with it.

Could someone please point me in the direction of such a tutorial (should it exist), particularly one that makes reference to the DCS 2.0 format?

Thanks in advance!

 

[kylebellamy]

I havn't found any myself however, I do use them a lot in my printing business so if you tell me what you want to know, I'll make up a tutorial for you. How's that for an offer?

As for the mode itself, it's invaluable in printing as it allows all sorts of unique graphics that could not be achieved using standard duotone methods or colored TIFF's (by the way, stay away from colored TIFFs as they cause all sorts of problems in the new RIP stations like mine).

You can email me if you like or just respond here. Tell me what you need them for and also any general questions you yhyave and I'll help where I can.

http://www.kylebellamy.com

 

[mistercitizen]

I havn't found any myself however, I do use them a lot in my printing business so if you tell me what you want to know, I'll make up a tutorial for you. How's that for an offer?"

>> Wow! Thanks for your generous offer. I always appreciate the opinions of someone with the expertise gained from working in the print industry. As you may understand, I don't want any "surprises" when printing my document.

"As for the mode itself, it's invaluable in printing as it allows all sorts of unique graphics that could not be achieved using standard duotone methods"

>>> Yes! That's EXACTLY why I'm electing to use the mode for my next two-colour job. I've used the duotone format before, and found it to be very limited due to only being able to only modify one channel of greyscale info.

Like I said, there isn't much info online about multi-channel mode. As I've never used the format, I'm concerned mainly about any problems that may arise when RIPing my Quark document containing DCS 2.0 images.

Some resources have suggested that some RIP's wont accept the format, or it will RIP incorrectly.

Also, provided I can get it to RIP correctly, are there any problems which may occur on the press? As there is more scope for experimentation in the multi-channel format, are there any possible image characteristics which may prove problematic for printers in any way?

Thanks again Kyle - a star for you!

 

[kylebellamy]

As long as the printers approach it as a duotone, then you should be fine. The really great thing about the format is you are not limited to two colors (alsways assuming your press can do more, that is).

For instance, one use of the format I saw was a christmas scene wherethere was a victorian street and the two colors were PMS295 and PMSRed 032. What the client did is to make the bows almost all red and then used the blue and red to create the rest of the scene.

When you look at the channels, there was the scene repeated twice except that in the red channel, the bows were very dark while the rest of the scene was a light, ghostly grey. On the blue channel it was the opposite. Very simple use but very effective.

Now if the client wanted something more colorful, a green like PMS3145 could have been used to do the garlands and the pine trees and that plate would have almost no image to it except for where the green was and the other two plates would, of course have the bits missing where the green would go.

The trick to doing this is to use the eraser like a paint brush with the Opacity set to something like 10% and using a soft sided brush. Zoom in on the area you want a color to be prominent and select the correct other channel (in this case say were doing the bows from the above example so select the blue channel) and carefully erase the area of where the bows should be. If you have both channels showing, you'll see the effect right away.

Now if you want the predominant color to be blue, then select inside the erased areas, invers and use brightness and contrast to lighten the whole and you should have a pretty good peice.

Granted for a really good peice, it will take some time to tweak all the little areas you want to have it work out but with practice you can do these things cold.

I use them mainly for things like scanning in hand written stuff that has to go on top of scanned line art so that it looks like the person wrote all the stuff right in but in reality it's a multichannel with black and reflex blue.

http://www.kylebellamy.com

 

[mistercitizen]

Here is an work-in-progress which I've used a similar technique as the one you have detailed in your previous post.

http://www.photoshoptechniques.com/forum/attachment.php?s=&postid=83512

I've been modifying each colour channel individually (as per your instruction), an option which allows far more scope for experimentation than the regular duotone mode.

I have tried to maximise the tonal range by overprinting different sections in varied amounts. This was acheived by making selections on specific areas and using curves to specify how much ink would print in that channel - hence the purple tones dominate the face, and the green tones dominate the jacket. I think this method offers a bit more precision than using just brushes, as the curves provide numerical data when modifying each spot channel.

I have increased the contrast of the whole image in this version - to make it a bit more punchy. Unfortunately,this has resulted in blowing out the subtle tones which defined the depth in the cap. I'll go back and use selections again, so the increase in contrast doesn't affect the cap.

Is there anyway I can anticipate how this will print? Are there any characteristics of multi-channel images which could prove problematic for printers, and should be avoided in my design?

Thanks again Kyle for your in-depth, well researched responses. I gain a great deal from your comments, and only hope that I can return the favour in the future.

 

[kylebellamy]

The only hurdle you'll face is the press operator. In my shop I have some who can do that image with ease and some who I wouldn't let near it! lol

Is this a two color Multi? If so, most print houses SHOULD be able to handle it. If it's three, shop around and see what they have to offer in the way of printing as it will take a lot of attention to detail to nail that.

I guess what I ned to also know is what you are printing this on, what press type, what PMS book your using and does it match the medium of type, that sort of thing. It might make a difference but I don't think so.

http://www.kylebellamy.com

 

[mistercitizen]

The only hurdle you'll face is the press operator. In my shop I have some who can do that image with ease and some who I wouldn't let near it! "


>>> But are my local printers going to admit that to me?!!

Yes, it is a two colour multi - the RGB conversion (it's a screenshot) may have made it look like three coolours were used (either that, or my masterful use of channels! LoL)

Yes, I know what stock I'm printing on and also my PMS colours. I guess it's just a matter of asking if my printer can handle it.

 

[kylebellamy]

It should be fine then. It will be apinfully obvious if the printer can't do it, right from the start. Also, you could request a press check which means that you are there while the press is running, grabbing a random sample to look at and compair.

Good luck and let me know how it turns out!

http://www.kylebellamy.com