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Layers vs. spot channels


J

jennifern

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Hello!

Here is a basic question...

When I am creating a spot channel in the channels palette, do I also need to create a layer in the layers palette?

I've already created some text in layers, and instead of starting all over again to create spot channels for the text, I was told I could just ctrl+click on the layer and copy onto a new spot channel. In that respect, I have a layer and a spot channel.

But if I am creating from scratch, do I create both?

Hope my question is not confusing...and hope the answer is easy!

thanks in advance [confused]
 
Using spot channels means that you want to use colours for professional offset printing that fall outside the CMYK range. These have to be kept into separate channels as, evidently, there is no place for them inside the CMYK channels. An example for spot channels would be a Pantone ink colour.
Layers are something different. Layers allow you to store part of the entire image separately so you can easily get access to it, and manipulate it.

So if you write for example some text, or part of a logo, and it is placed on a separate layer (text by default is), it will simply be added to the entire image when you keep the layer's visibility on. But it will not be printed separately.

When you Ctrl-click on the (for example) text layer, you will get the same effect as right-clicking on the text-layer icon and choose "select layer transparancy". When you then go to the channels pallette and press the second button from the left (save selection as a channel), you will have the information of the text layer saved as a channel.

In fact, you can see a channel as a container for information that may not be mixed up, like the R, G and B info, mask info or spot channel info. Every channel is in fact a greyscale image.
Keep the layer is you want to go on working on the file. But only the channel will allow you to store separate information, and, evet. to reload than info as a selection.
Hope this answers your question.
 
Many Photoshop users forget the incredible possibilities of channels.

Basic channels: contain the infoirmation that has been separated by the mode you chose. RGB for example has an R, a R and a B channel. Then there's also a composite channel, but that is of noreal use for manipulation.
Lab mode has three channels, and the lightness channel is the ONLY perfect greyscale image of your coloured image. This you can use for everything that you prefer to do in black and white (greyscale) like selecting edges, using some filters, adjusting brightness etc... Just chose Image>Mode Lab and select the lightness channel.

The most fascinating thing is that Channels are like ordinary greyscale images. You can manipulate them, apply filters etc.
And everytime you can load the image of the channel as a selection.
What can be more handy? (except for the Undo button of course...)
 
spot channels vs layers

Erik-

Per your response...
When you Ctrl-click on the (for example) text layer, you will get the same effect as right-clicking on the text-layer icon and choose "select layer transparancy". When you then go to the channels pallette and press the second button from the left (save selection as a channel), you will have the information of the text layer saved as a channel.


...I had been going back and creating spot channels (black pantone color) for individual lines of text. after about 20 spot channels, i was not able to create anymore (i got to about 20). i posted a message about this in a forum and was told that i should not have that many spot channels. Now, I am stuck again.

If i have 50+ lines of text that i need to "identify" with a particular ink for the printer, don't I have to create each as a spot channel?

Here is the piece I am talking about...
 
Is there a specific reason to do this in Photoshop?

If yes, I suggest you open a white document of the size you need, then write every line of text on another layer and make your lay-out by moving the layers until you get a pleasing effect. (the grid can be useful: show>grid ). Do choose a good anti-aliasing. This is probably what you did, didn't you?

Then click on the eye icon of the white background so as to make it invisible. Then, in the upper-right corner of the layers palette, click on the small triangle and choose "merge visible". When you now control-click, you get only one spot channel.

Why a spot channel is my next question? You need an EPS?
When you use black text on a white doc, your C, M and Y channels will be empty, and your K channel will contain the black info (the text) You may want to check in the channels palette. This must be sufficient for every printer, because spot channel is just a label on a container, nothing more.
 
Erik-

Thanks for the info.

I am building this in PS because it is the only program I have (don't yell at me! i'm just starting out, and i'm broke!) :)

I will be saving as an EPS file (or DCS?) since the printer has to take my PS file, plug it into his PS (MAC based) and/or Quark to send through the printing process.

I just spoke to the printer and he mentioned that I only need a spot channel for the "X" typefaces I'm using throughout the materials...that I don't need spot channels for each line of text. So maybe I got nervous and jumped the gun.

Now that I think I know what to do, my next real concern is saving the file properly since I ran into this problem last time with the printer and not being able to get him the files correctly...I didn't get the results I wanted.

In this case (saving the files), he told me that I don't merge or rasterize any layers, and that I just need to "flatten"...is this correct? I'm not sure why this is so difficult for me to understand...maybe I am just very nervous and wanting to get my ideas to print out and be beautiful!!

(I'm sure you know more than the printer and me!)

thanks again!
 
Hiya Jennifer,

See if this helps understand things a bit better.

Text 1 is made up of CMYK, it gives a final black which requires 4 plates to be made. Compare the Colour Picker to each Channel.

Text 2 is made up of only Black - 100% K.
Only one plate needed to print.

When using only 1 solid or spot colour it is not really necessary to specify it in Photoshop. This applies only for a card or poster such as you have asked about. (It is a bit different if it was for a magazine page.)

The printer only uses the artwork to make the printing plate. He could use any colour of ink using this same PShop file.

I would make the text 100% K (Black) and supply the printer with the native Photoshop file and let him do the lay-up in whatever programme he uses.


Hope this helps, just ask if you need more info.

Cheers Al
 
When the printer said he only needed a "Spot Channel" he really meant that he only needed a single tone ie: greyscale (single channel) file to make the single plate for printing.

Sorry for the long winded posts, but I hope the info is useful anyway.

Again, ask (here) if you want further clarification.


Cheers Al
 
Hiya Jennifer,

As long as you learn somehow :righton:

Here's a greyscale, just make the toolbox colours default black and white. Do your text. Flatten it and save.

Give it to the printer as a TIF file and forget about eps and DCS.

Simple is the best, Al
 
that's great! thanks for the post.

question: how did you get the entire text to appear in the channel? (i've already created the layers so i'm going back in order to avoid re-typing everything)...or did that occur after you flattened it?
 
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