transparency washes out other elements 1

[matilda13]

I have been trying to place an image (A) with a transparent background into a frame in InDesign CS4. Every time I do this, it washes out a series of images (B) on the page (these images are all linked to the same tiff file). Not everything on the page is washed out, only B images.

- I have tried placing A as a tiff (w transparency saved) and a psd file.
- I have tried creating a new layer to place A in, and locked the layer containing B.
- When the file is exported as a pdf the issue with B persists.
- As soon as I delete the frame containing transparency, B reverts to former intensity.
- The same issue occurs with B when I change the opacity of an object drawn in InDesign.

Any advice would be greatly appreciated...

 

[matilda13]

OK, so the issue was that image A is CMYK and B was greyscale.

How do I take down a thread if I realise I may be wasting your time?

 

[apepp]

...i wouldn't worry about taking the thread down, someone else searching may benefit from your post, even if you have solved it yourself...

...the issue you have come across is a display rendering issue of indesign and how it deals with transparency...

...the effect appears on screen to shift greyscale images on a page that also uses transparent effects (such as imported PSD or indesign's own effects like drop shadows)...

...by default indesign uses the CMYK blend space (edit > transparency blend space > document cmyk) and it is this that effects the display of transparency with greyscale images on the same page...

...the other area is in the preferences (appearance of black > display all blacks accurately)...

...if you have these settings applied then you are best to leave them as they are, the preferences option to display all blacks accurately is a useful one. The only exception to this is the blend space if printing to a desktop printer, in which case you can get better prints using the RGB blend space instead. However for commercial printing keep it on the CMYK blend space...

...as you have discovered greyscale images may appear lighter on screen when a transparent effect is in use, but the actual black ink percentages do not change, it is purely a screen rendering anomaly of indesign...

andrew

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http://www.apepp.info

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[matilda13]

Thanks for your response, Andrew.

I was initially setting up this document for on screen presentation but I will eventually need to make elements of it print ready. I'm with you as far as sending CMYK to commercial printers but I've never been in a position where I have a greyscale image as part of the artwork. Can I leave the image in greyscale or should I change it to CMYK when it comes time to print?

 

[apepp]

...that is a very good question about whether or not to leave greyscale images as greyscale or convert them to cmyk black and white when printing your artwork in cmyk...

...the answer to this really depends on a number of factors, getting decent greyscale images to print in black ink alone can depend on the paper and also the actual quality of the source greyscale images you have (decent highlights and shadow areas), the same would be true for cmyk black and white...

...generally it is safer to stick with greyscale, as when converting greyscale to cmyk black and white you have to be careful with possible underlying color casts not seen on a monitor until printed. Having a very well calibrated monitor helps, but no real substitute for seeing a hard copy contract proof from a print provider...

...cmyk black and white images can indeed look much nicer than simply black ink greyscale, but for a decent conversion to be made I would suggest discussing with your print provider who can hopefully provide you with a profile conversion technique to get a decent cmyk black image onto a given paper type (either uncoated or coated paper)...

...usually though, cmyk black and white images are pretty well reserved for what could be called "high end" bespoke printed photography work or posh corporate brochures that can benefit from a bit of TLC (tender loving care) in the process...

...if your particular artwork isn't really of that nature then I would leave them to be greyscale. However if the artwork is "worth a test" then i would discuss with your print provider what profile conversion techniques they would suggest, and whether they have profiles they can provide for a decent conversion...

...if they don't have custom profiles, then the usual technique would be to get your greyscale images looking their best before converting to cmyk (around 95% shadow areas and around 0%-4% highlights). Then convert to a CMYK profile (edit > convert to profile in photoshop) and using a GRACOL, ECI or FOGRA ISO 12647 profile (coated or if available an uncoated version if destined for uncoated paper). ISO 12647 profiles are considered in the trade to be safe profiles when performing color conversions to "unknown" color workflows...


andrew

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http://www.apepp.info

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[matilda13]

Hi again,

So I sent the file to print with both the greyscale images and the CMYK tiffs with transparent backgrounds.

I had to send it as a PDF, I saved it as a high quality print.

When it came to proofing, the issues with the washed out greyscale persisted. Also, 4 out of my 6 of my placed tiffs had a white overlay (at about 10%) where the transparency was supposed to be.

Should I save it as a different pdf preset?

Regards

Matilda

 

[apepp]

...if you sent the PDF file with the preset "High Quality Print" then your PDF is preserving transparency (Acrobat 5 - PDF 1.4)...

...this would mean your print provider needs to flatten the transparency in their workflow (unless they use the Adobe PDF Print Engine)...

...without seeing the artwork you have sent it is difficult to problem solve, but i would suspect you print provider has encounter output issues when trying to flatten the transparency in the PDF...

...it is better in unknown workflows to export as PDF/X-1a:2001, and have the transparency flattened in the resulting PDF file...

...if you can post a download link to the PDF file you sent, it will be easier to determine if the output provider has proofed the PDF 1.5 correctly or not, and to determine whether there is an underlying issue happening in the artwork...

...one test you can do is to rasterize the PDF in photoshop (CMYK mode) and have a look at the result...

...also open up one of the greyscale images used and compare it to the PDF with the eye dropper to determine the % of black ink used...

...the % of black on the greyscale images in the PDF will almost certainly be exactly the same, so this would indicate an issue with the output providers workflow...

andrew

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http://www.apepp.info

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[matilda13]

Hi Andrew,

Thanks again for your post.

Because of scheduling issues I have swapped printers. I sent the new printer a PDF with the preset you suggested (PDF/X-1a:2001). I made them aware of the prior issues and they printed off in A4 to get an idea of how the file would perform.

I haven't seen a proof yet but they contacted me to say that within the bounding box of the placed image (the area that was previously 10% white) there was the same issue but this time it has a blue/green tint to it. From all reports the contrast of the background image is consistent across the file, unlike the result from the previous proof.

The current printer has suggested rasterising the file and sending him a PDF.

I thought I was clear on his request but I am not entirely sure how to go about this. I tried exporting the InDesign file as jpegs and converting them to PDFs but there was still onscreen inconsistency with the contrast of the greyscale image across the different pages. I will send you the first PDF mentioned in this post via You Send It.

Cheers

Matilda