It sounds like what you are doing is preparing a file that will print on a digital press: 4 color process inks along with a spot opaque white ink. If this is the case, the preparation of the white ink requires that it is specified a spot color, named "WHITE" and the color makeup of the spot ink is 100% magenta. Most importantly is that the color is made a spot ink. The color recipe (100M 1Y) will not have any bearing on printing the white ink.
I'm guessing Jeffery is right, but the yellow percentage would be coming from compression artifacts when you save as JPEG. Save out as a lossless format like .PSD. You'll need to do that for a spot channel anyway–JPEG doesn't support extra channels
Thanks for your help. Correct Jeffrey, I am preparing artwork to print on a mimaki UV printer. The printer is set up right and we have other art work that I have no trouble with- whatever is 100% M prints spot white.
I'm not sure whether I am preparing my artwork correctly for this project and am still a bit confused.
Rob, I need to place the image into Indesign- should I try to place a PSD instead?
So do you think the problem is occurring when I save the jpg- it's not recording the colour values correctly? Or might it be that I have converted it to cmyk in the wrong way in photoshop? Or is it about the way I'm placing the image in indesign? Or exporting to pdf from indesign?
As you can probably tell I am still a learning artworker.
I've tried a test print and it is printing out in bright pink!
Thanks again for your help
When you make a jpg it adds com compression to the image which results in ‘extra’ or ‘different’ colors in areas. To preserve the pixels without alteration you need a ‘lossless’ (no compression) format. Whether this is jpg, tiff, png without compression or the PSD itself.
I would probably place the PSD (thought I think someone said this could have bad consequences for vectorized text/art).
For coating applications we usually assign a ‘spot’ color as mentioned. You would select your area, move to channels, create new spot channel and fill it with 100% magenta.
edit: I kept thinking about this imagining how it would work - this will only give you a big pink image as well. surely your printer is looking for another 'channel' or color
For this, I would select the solid white as you had done, then navigate to the magenta channel and fill those pixels with solid black – the channels are basically your CMYK plates so you’re telling it whatever was white in the composite will now be 100% solid in the magenta channel.
You should not be using JPEG for print. When you save as JPEG, compression is applied; artifacts are born; pixels change. When saving in Photoshop for placement in an InDesign Print layout, there is no reason to save in any format other than PSD.
The printer is set up right and we have other art work that I have no trouble with- whatever is 100% M prints spot white.
But the color you have setup in InDesign is a spot color swatch right? Like this where the Color Type is Spot and not Process:
The JPEG format can't be saved with a spot color channel, so you must be using process magenta in the Photoshop file and so it would print pink.
If you need a spot color from Photoshop it has to be set up as a Spot Channel like this—the name of the channel will have to match the name of the spot color you are using over in ID:
Thank you for this.
I have tried setting the artwork up like this and creating a 'spot' not 'process' colour in ID. The only thing is that now when I export to pdf to print from ID, the white is appearing white and not magenta. I have checked on our other ID documents that we print in white- and the magenta we use is a process colour- our printer is set up to read process 100% magenta as spot white as far as I can tell...?
The other artwork that we print white is done purely in ID which is why I think, I have had no problems with it before.
I have placed the PSD file (with a merged 100%M colour fill) in ID ... there is slight progress in that now when I use the eye dropper tool- it is saying that the magenta is 100% magenta. When I export to pdf I am going on the compression settings and under 'colour images'> 'compression' choosing 'none'. It is still printing pink not white.
Do you have any other ideas?
Thank you !
1 person found this helpful
our printer is set up to read process 100% magenta as spot white as far as I can tell...?
In that case, how would you print actual magenta? Have you tried printing it (or if possible, previewing it in the RIP, to avoid wastage) as advised, with a spot colour called 'WHITE', that is specified as 100% magenta?
It's common practice to make special colours (die cutting, varnishes etc) look magenta, but really, it can have any appearance on-screen. It's the name of the spot colour that triggers the RIP to process it as intended.
Oh I see. I will test it with the spot colour setting. So our printer should automatically recognise 'WHITE' and print it white..? This makes sense.
Could you select an object in InDesign that is outputting correctly, open it's fill swatch an screen capture it for us?
I wouldn't like to make presumptions about specific equipment I've no experience with, but yes, I'd predict that to be the case.
What if you want to print magenta?
.... i think we just don't print in magenta...!
but we have different colour profiles- so I could print in magenta if I drop the artwork to a different profile- one that doesn't print in white and has a different pass rate ...
I'd expect that you'd be better off going back to the original pattern (before you coloured the white with magenta). Place that in the compound path, copy the path, paste in place, delete the image from the copy, colour it with a spot colour called 'WHITE' and set it to overprint. But of course, your equipment might work (or be configured to work) differently than I'd expect.
Ah. By 'profiles', do you mean hot folders that make the RIP apply different settings to jobs? Do you have any training on the RIP side, or have anyone there you could ask about this? Because I suspect the solution lies on that side of things.
Yes. We have hot folders that apply different conditions for different products we print on. I just drop the pdfs into the right folders.
I just don't know why the magenta in the placed image is not being recognised...?
OK, I will try to talk to someone RIP side. I just wanted to make sure it wasn't my fault in the way I am preparing things in Adobe.
Thanks for your help.