Spot Color Separations with Photoshop

Tina from Texas, USA, using Photoshop 5.5 with Windows 98, writes in with:
[Quote:] How do I create spot color process separations using Photoshop starting with a full color photo image? This is for outputing to film to screen printing t-shirts. Thanks in advance for your help. Tina

Tina, it's easy -- but first let's see if you want spot colors or process separations...

Creating spot channels:

Process color separations are films (often called "printers") used to print a full color image. These four sheets of film have been separated into their individual color channels so they'll print properly using CMYK inks (Cyan, Magenta, Yellow and Black). Of course this is a highly simplified definition.

Spot color separations are films that do not necessarily use the full color image to derive the image value which will be used. Spot color is usually designated by the designer or artist. Spot colors do not come from Process Color Separations unless they are added as separate, individual pieces of film.

For screen printing, we assume you mean "Spot" color. In this case you'll need an individual "Spot Color" and its corresponding sheet of output film in order to burn the screens and print the T-Shirts.

For each color you wish to (screen) print, you'll need to create a new spot channel or convert an existing alpha channel to a spot channel.

To create a new spot channel:
1. Choose Window > Channels to display the Channels palette.
2. To fill a selected area with a spot color, make or load a selection.

Now do one of the following to create a channel:
* Ctrl-click (Mac OS: Command-click) the New Channel button in the Channels palette.
* Choose New Spot Channel from the Channels palette menu.

You will see a new Channel icon appear at the bottom of the Channels Palette, with your selection

If you made a selection, that area is filled with the currently specified spot color.

You'll need to assign a color to this channel.
* Click the color box, and choose a color (Select from any of the color systems included with your Photoshop program. If you create your own custom color, don't worry, the screen printer can mix up the ink color you need.

We do not know if you'll be using transparent inks, but if you are not then use a value of 100% to simulate the opaque silk screen inks. The channel can have grays and gradients of the ink, however you need to make sure the film will be output at the screen frequency required by the screen printer.

KEY RULE: You MUST give each Spot Color Channel a unique name. This signals to the software that it is not a process color, and that it must be imaged as a separate piece of film.

TIP: it helps to name the channel the color you'll be printing.

Converting existing channels to spot channels:

If you have edited and modified one of the existing Process (CYMK) channels for use as a Spot color, then do one of the following:
* Double-click the alpha channel thumbnail in the Channels palette.
* Select the alpha channel in the Channels palette, and choose Channel Options from the palette menu.
2. Rename the channel (Again this is important)
3. Select Spot Color
4. Click the color box, choose a color in the Color Picker dialog box, and click OK. Do NOT pick the same color again. You don't want two films of the same color.

Finishing:

Before outputting proofs or films, you need to know the screen process your printer will be using. Some substrate stencil processes use a film positive, others a negative. Consult your printer.

Choose Image > Adjustments > Invert to apply the color to the selected area of the channel.

REMEMBER: you can edit those channels using brushes, type, etc. so long as you stay to black and white ONLY.

Have fun... send us a thumbnail of the finished shirts.

Comments

[Billy Soetrisno]

Color separation in Photoshop is fairly easy for me...mainly if you talk about simulated process utilizing the channel window
Personally i think Color Separation in Illustrator is way easier since it consists as a vector image.
Let me know if anybody needs some help..baboza@yahoo.com

[jacqueline]

hey everyone,

i'm a designer for most things, including apparel graphics and do my own color separations. illustrator is my drug of choice, but occasionally use photoshop depending what kind of art I'm working with. color separations in photoshop is fairly easy, compared to illustrator. i always look at illustrator as the manual way to do it, and photoshop as the automatic because there are less steps involved. first, indexing was always the more precise way to separate spot colors in photoshop, but some people chose to do it the ways that they are most comfortable with. just think of it as dissecting the colors in your image and creating different layers/channels for each one. try to use the least amount of colors though, or else your vendor will kill you set up costs and labor! think of how colors interact when they overlap...the whole color theory idea, yellow and blue make green, so if you need green in your art then overlap those two layers.

sorry nick, don't know how to do process simulation seps, good luck though....are you guys by any chance looking for freelancers!

[Nick]

The best way to separate an image for silk screening is INDEXING. This process involves converting you image to an indexed image and selecting a custom color pallet. You then goto your channels, select a color from your indexed image and make a channel for it.

I'm currently trying to learn process simulation sep's. If anyone knows anything about it. Help me out!

Oh, I work full time as an in house designer/color separator for a print shop/clothing company. Anyone heard of Atticus Clothing?

[jpod]

HOLD ON GUYS, if you are a designer, and you send your stuff to a printer, HE WILL DO THE SEPARATIONS. Pre productions houses have people who do this for a living, and in my experience, they all use Photoshop 5.5.
If you have a photo that you are separating, or something complicated, they will do it for you.

[Vincent]

Hi I'm confused with tshirt spot color separation, is there anyone know how to do spot color separation on multi-color gradient?

[bret]

Hi Daliah,

Photoshop is always going to try and rasterize an .ai file, because it is a raster program. Newer versions will import it as a smart object, but still completely uneditable.

However, illustrator files are perfect for color seperations, if you have illustrator or coreldraw.

Also, you can go to select/color range and with the eye dropper tool that comes up, select a color of the ai file. Make a new layer, and fill that selection with color, and name the layer the color it will be. This only works if the ai file is to size however. You can turn all other layers off, and send that one layer to the printer, and theres your color sep!

Hopefully, ive been of some help.

Bret

[Andre Beauvais]

Well does anyone have a working technique for photoshop cs3 most of these people are using 7 and 5 none of these seem to be helpful. Or can someone send a link that will help?

[Cao]

Graeat tip. Very useful and easy to follow. Thanks.

[babal]

hi m babal
i have a photograph i want to print the photograph with screen printing
on t-shirt in spot color i have photoshop-6.0 pls give me best advice with pitchure help and tell me which tools is use full for me to do color seaprations

thanks

[kamal jeet]

hi m using a photoshop7.0.1

How do I create spot color process separations using Photoshop starting with a full color photo image? This is for outputing to film to screen printing for t-shirts.

thanks in advance for your help. kamal jeet

[curly]

The spot channels thing is great- works like a charm, but how can i bring a multichannel document into indesign or quarkxpress to make a multi-page document?
Photoshop only allows you to save it as a psd file which is not importable into other applications.
The only solution I could think of was to separate the illustrations into CYAN MAGENTA YELLOW AND BLACK, and then just specify to the printer to print the pantone colors instead of C,M,& Y. But then its impossible to get a preview with the pantone colors...

Any suggestions?

-curly

[George]

I empathize with Toni's comments above (scroll up).

Let me explain myself "it's easy"... after reading this article, I am left with no "APPLICABLE" understanding of how to print an image to a tshirt - using as you put it "spot color channel" or otherwise. Honestly, its frustrating.

So... if its possible would you take one image, say of a human face, and explain this process step by step from a single given image to the final result on the printer. Providing an image, I believe, would help simplify matters in that it would serve as a common reference point.

There's a tutorial here on 911 in the "tips and tricks" section on COLOR SELECTION which seems to adequately convey the process of color selecting given areas of an image. I would love to see that same simplicity applied to this process of printing "PICTURES" to thsirts.

OTHERWISE: can someone send me step by step ("dumbproof") instructions on how to print a picture to a tshirt using color selection or whatever you call it.

Also... i need to know in simple terms how to determine whether my printer is capable of printing - as you call it - "PRINTERS". GEEZ!

[mon]

how is a "4 color separation" (process colorsep - is this the right term?) done in photoshop6,7 and CS for silkscreen printing? can anybody help me, pls...

[MegaGearX]

Too many SPOT layers!!!

How do you merge SPOT color layers? I have too many of the same color layer (One Black and 9 Yellow), but different things are on them. Photoshop 5.0 doesn't give me the option, even when I select all the layers at once.

[Full Color Printing]

GOod resource and information..

[Steffani Coverson]

For those of you trying to get your effects to show up and Photoshop flattens them out when you convert them to spot...this technique has worked for me. First select the areas of the image that are going to be one spot color (for example 292C). Copy and paste them into a new photoshop document keeping the same resolution, etc. Then convert the image to grayscale mode. Next do an "auto contrast" adjustment so the blacks are black and the whites are white, there may or may not be plenty of greys inbetween depending on the effect you used. Next convert it to bitmap. In the options, keep the dpi the same as your overall image and select dither from the menu below it. Yes this will pixellate your effect on screen but unless your resolution is really low (like under 100dpi) it will never print on cloth that way. Also keep in mind, in a way, screens are pixellated. They are just comprised of many holes that the ink is squeezed through to make the design. Once your image is converted to this bitmap select it and paste it back into your original document on a new layer. From there, you can follow the technique described by the gentleman before me. You would just select that specific layer and in the channels palette create a new spot channel for it (pick the color of course it is supposed to be instead of black) and voila! - If this did or didn't make sense to you or you tried it and you got really confused, please let me know. I'm working on becoming a freelance technical writer to supplement my daily income and would appreciate your feedback.

[Toni]

I have a logo that I've created with effects on each layer. ie: embossing, shadowing, ect. I need to color separate the two layers, one being black and one PMS 292. When I select the contents in the layer and make a new spot channel it takes the effects off of what I've created. I can get it to separate but when I assign it to the proper channel it takes my effects away and makes them solid colors. If that was the case I could do it in Illustrator. HELP!!!

[Clark Haddock]

I tried following these instructions but I am still not sure how to do color seperations. I am very new to this and I do not even konw what comment about "Double-click the alpha channel thumbnail in the Channels palette" means. which on is the alpha? how do I put in regestration marks, work on the dot patterns, etc.. How do I create a solid underlay? What if it is not a cmyk and is only 2-3 colors? Do I go about it the same way? Sorry for all of the questions.

[olumide]

dear,
you've made my day,i have being wondering how to screenprint multicolor arts on t-shirts with ease for long,thanks a million

[Daliah]

I have a layered PhotoShop file that I need to make the background layer PMS 282. I can create a new spot layer channel, but when I do, the layer above becomes transparent and my entire image is now blue and I need just the background to be blue and leave the top alone.

Any help on how to do this would be greatly appreciated.

thanks, Daliah

[David]

hi, ive been looking for a way to efficiently color separate. i haven't been using these illus. or photo. too long, so im not exactly what one would call a master. but these instructions were very helpful, except i can't figure out how to import an ai. file into photoshop and not have it rasterized or pixelized. (unless there is an easier way of making selections without the magic wand) can anyone please help?

-dave