I have no idea

[mimosatexas]

hmmm I did it exactly the way Pierre described. I will play with it more tonight and tomorrow.

It looks like you missed the inversion step for the underbase.  It should look like this:

[mimosatexas]

Just a note, I didnt adjust that at all, just inverted.  I would probably play with the curves a touch to give it better contrast and to adjust for gain.

[blue moon]

this one is easy.
convert to grayscale and invert. This is your underbase.
convert to CMYK and select the magenta channel. that's your color.
copy the underbase and adjust the halftones until you eliminate most of the things below 50% (with a slider). You'll be left with the highlight white.

experienced separator can have this ready for you in 15 min.

pierre

this is a great post especially for a Photoshop novice like me. Learned so much especially as an example file was posted so we could easily follow it step by step. now two question, if you would want to underbase the text too how would you go and do that? And which slider are we talking about for adjusting the highlight white? Curves and then set output to under 50%? I Love learning all these things:)

See above for under basing the text. If the white fill stays when black background is added it will turn solid after is inverted.
Yes, in curves. Grab the left point (when in ink mode), and drag it to the right. Then grab the curve and pull it down. You should have all of your solid white left and only a little bit where the highlights are needed (10-30%).
Pierre

[Prosperi-Tees]

Ok looks like I got some messing around to do. Im doing this in CorelDraw and Corel Photo Paint and trying to replicate what you guys are talking about.

[Gilligan]

this one is easy.
convert to grayscale and invert. This is your underbase.
convert to CMYK and select the magenta channel. that's your color.
copy the underbase and adjust the halftones until you eliminate most of the things below 50% (with a slider). You'll be left with the highlight white.

experienced separator can have this ready for you in 15 min.

pierre

this is a great post especially for a Photoshop novice like me. Learned so much especially as an example file was posted so we could easily follow it step by step. now two question, if you would want to underbase the text too how would you go and do that? And which slider are we talking about for adjusting the highlight white? Curves and then set output to under 50%? I Love learning all these things:)

See above for under basing the text. If the white fill stays when black background is added it will turn solid after is inverted.
Yes, in curves. Grab the left point (when in ink mode), and drag it to the right. Then grab the curve and pull it down. You should have all of your solid white left and only a little bit where the highlights are needed (10-30%).
Pierre

I'm losing the detail in the pink, it loses all the texture from the "Gro" swooping down under to the "ps".

From what I can tell it seems like it's the black channel that brings this back in the CMYK version... but I can't figure out how to use that as a knock out channel.

[screenxpress]

Gerry,

Try this in Corel/Paint -

1. Select .pdf in Corel and Edit Bitmap to open Paint
2. Image/Convert to Grayscale
3. Save file as Magenta.cpt
4. Select (box) around the entire canvas to get the entire image selected (along with the canvas)
5. Image/Transform/Invert Colors
6. Deselect
7. Select Magic wand and set to 5%
8. Select just the outside (around the image for the canvas) and delete
9. Deselect
10. Save as UB.cpt
11. Drag the UB.cpt file into Corel - double clicking will open up in paint
12. Select Print - Device Independent Postscript file
13. Color/Print separations
14. Separations/Advanced
15. Black checked/Freq=45/Angle=25 (options)
16. Click Ok to output a .ps file
17. Open UB.ps file (mine is Ghost) - Yours is ? to print ps files
18. Print out the UB as halftone
19. Repeat 11-18 for Magenta Plate

That printed halftones for UB and Magenta for me.  Prolly needs some tweaking but maybe there's something there you can use.

And I would print this with just White for the UB and Text, flash and top with Magenta.

I did have some doubt about that lone dot above the 'g'.  On a Black shirt, is it supposed to be White, or Black?  The steps above have mine as a White Dot.  Hard to figure since your pic was on a white canvas but mentioned printing on Black shirt.  I'm sure you'll figure that out, lol.

[Gilligan]

Think I figured out my problem.  I took the black channel that I made and used the magic wand to select the white, invert selection, invert image and then copy and paste it to my pink channel.

Not too bad for 3 color (two of them being white!)

[StinkyDaddy]

This is a super thread. The way Pierre simplified the seps has made me start to think about the way I've been doing things. Thanks.

[blue moon]

OK, so here is what you get if following my directions (see image below).

this would not pass for our customers (we market to ppl wanting more, it's our business model and it does not make it better, just different), but for somebody wanting a quick down and dirty, it could (should?) work.

There are several issues with these seps.
-As Gilly pointed out, some dark detail is getting lost. This can be adjusted in the ubase and hi white. Select the black CMYK channel and ctrl click on it. this will load the contents of your black channel as selection (you will see the marching ants around it. Not all will be visible as only the areas that are above 50% will show as selected. Less than 50% while selected will not show as such. Now click on the white channel (maintaining the selection), open the curves and adjust the areas so there is less white in them. You can also try doing it with the delete key without going into the curves. This will take out the white ink in the areas where the black is printing. BINGO! more contrast).
-second, there are actually two colors in the art. Red and magenta. If you look at the yellow CMYK channel, you'll see where the red has to be (magenta and yellow make red so the yellow areas are actually red). Take the yellow channel, duplicate it and bingo there is your next color!

at this point I think this a passable print. Experience will tell you how much to play with the curves to get everything blending right. This is impacted by your press and ink system. Easy thing to do which

this (for next 15 days) is the link to download the actual seps generated this way. No, it has not been tweaked (it needs a little bit) and the underbase is peaking, but it will give you an idea.
Photoshop seps


pierre

[blue moon]

here's what the revised seps will look like in PS (as mentioned about a million times before, they are not a accurate representation of what it will look like in print).

pierre

[Dottonedan]

The problem I think you are all overlooking is that fact that this art (is presented) on a white background...and you assume...that you take what you have and you make a mask of that. With this actually being printed on a black tee....and you look at that original art, you have to imagine that intent...of the original artist (and your customer).  The intent...is for this texture to fade off to the shirt (or background). In the case of the presented art...it's a white background. When going on the shirt...it should trail off to the shirt color, making it look more like it was "intended" to be on that background.  Follow me?  Otherwise, your representation on the black tee it going to leave the edge choppy and hard like a blob of image "pasted" on a the shirt rather than "a part of" the shirt design.


In addition, the art has not just magenta, in it, but true red...and even some purple. The purple can be questioned as to wether it's really needed. You can't get the true look of this image with just magenta tho. The deeper shadows are where the red (is knocked out of the base..and an even darker custom selection was created to knock out of the red...to the shirt. You can see my color list and order.


How do you get a good true base from this art when it's placed or comes in to you with a white background?  Very tricky. Thats why an artist is good to use for some jobs. THIS job, is not as easy as it looks.  Can I give you a good tutorial on how to do this like Pierre did?  Yes, but it takes time and I don't have much of that.  For 70 shirts, it might be best to use one of the sep programs and get whatever results come out and tweak if you can.  To do it best, takes more time, but your customer may be just a happy with the sep program results...and added colors. Then again, maybe they don't tell you they don't like it and assume this is all the best you can do...and eventually go to another shop to try later. Who knows?

[screenxpress]

I may be mistaken but the methods discussed speak of PS which is what I would be using on this.

I thought gerry only had Corel which is what I presented, although it was just an example

Did I miss a post that Gerry has PS?

[Prosperi-Tees]

I may be mistaken but the methods discussed speak of PS which is what I would be using on this.

I thought gerry only had Corel which is what I presented, although it was just an example

Did I miss a post that Gerry has PS?

You are correct Wayne, I am only working in Corel and PhotoPaint. I will try your method this afternoon, thanks for the write up!

[Dottonedan]

I may be mistaken but the methods discussed speak of PS which is what I would be using on this.

I thought gerry only had Corel which is what I presented, although it was just an example

Did I miss a post that Gerry has PS?

You are correct Wayne, I am only working in Corel and PhotoPaint. I will try your method this afternoon, thanks for the write up!

Well, THERE is your problem. LOL.   Just kidding.  For Corel, you might also want to try following Full Spectrums examples for pulling colors. You may get one or more good channels to use for seps out of it.


Still tho, whatever program or method, you want to fade that art off to the shirt color.

[Gilligan]

Screw Gerry! We don't give a sh!t about him, we just want to argue/learn about how is it best to separate this! 

I just assumed that Corel has some equivalent way of handling the steps we are discussing... but I don't really know.