Eliminating transparancies

[drdavendallas]

I have designed a book with almost 200 photographs in Affinity Publisher. I have to upload a pdf of the book to my book publisher. However, they are flagging my pdf file with the following message.

We detected an element that may be transparent within your file. We strongly recommend flattening or removing any transparencies in your file. 

1. How do I find a file or two that may contain transparencies?

2. I've read several times articles about flattening. I am simply grouping layers and rasterizing to flatten. Is that the easiest thing to do to "flatten" transparencies?

 

Thanks for your help.

[NotMyFault]

Hi,

there are many options. Flattening (in Affinity) does not include matting (replace transparency by a selected color).

Ad 1: identify transparent areas.

If you have Photo, open the file in Photo nd use the channels panel to only inspect the alpha channel.

If you have only Publisher: add a channel mixer adjustment, and use specific settings:

R, G, B: set R,G, B to 0, and alpha to 100%

Alpha: set all to 0, and offset to 100%

This maps the alpha channel into a greyscale image.

You can use curves or levels to further boos contrast, to see areas which are not 100% alpha.

Ad 2:

As explained, flattening does not include matting (removing transparency).

The simplest method is to add a white or black rectangle as bottom layer to every master page.

 

PS: you may export as PDF/x 1a

 

PDF/X options are pro-print PDF presets that create PDF files that output to CMYK color space and can embed all fonts.

• PDF (PDF/X-1a:2003)—based on PDF 1.4, flattens transparency, no color management

 

https://affinity.help/publisher/en-US.lproj/pages/Publishing/publishPDFFiles.html

Edited October 24, 2022 by NotMyFault

[drdavendallas]

Thanks for your quick responses.

 

I'm just a 90-day wonder at Affinity, so I really appreciate your help/

Stupid question maybe, but here goes.

 

Where do I find alpha channel?  On Histogram, I have Red Blue and Green Channels, but not alpha.

Seriously, thank you for your patience.

[NotMyFault]

5 minutes ago, drdavendallas said:

Where do I find alpha channel?  On Histogram, I have Red Blue and Green Channels, but not alpha.

The histogram does not show the alpha channel. 
but you can map the alpha channel into the regular RGB channels, as i explained in m y first post.

I will upload an example file with that adjustment layer in a minute. 

[NotMyFault]

Here the file. Copy the two adjustments as top layer into you file. Black indicates transparent areas.

alpha to rgb.afphoto

[drdavendallas]

Sorry .. where is top layer of my file found? By file you mean my whole book?

Sheesh -- I'm sorry for coming across so dull.

[NotMyFault]

no worries. Lets try one method step by step

You file normally contains several pages (master and regular pages).

1. Select the first master page
2. Add a rectangular shape in the exact size of the master page
3. Set its Fill color to pure white
4. Use the move tool. Move the rectangle layer to the bottom position in the layer stack of the master page
5. repeat this process to all master pages.

BTW: any chance you can upload the actual file, or at least a few pages from it?
 

[drdavendallas]

This is the file of the entire book's innards. I hope you can see the images. I have them linked instead of embedded.

So, this is where I have a transparency someplace.

Granbury Book 3-x.afpub

[NotMyFault]

9 minutes ago, drdavendallas said:

This is the file of the entire book's innards. I hope you can see the images. I have them linked instead of embedded.

So, this is where I have a transparency someplace.

Granbury Book 3-x.afpub 11.88 MB · 0 downloads

Hi,

I create 2 master pages, added a white rectangle to them, and assigned the master pages to all regular pages. Should be fixed now.

 

The advise is to always use (and start with) master pages when working in publisher.

I hope this solves your issue.

Granbury Book 3notransp.afpub

[drdavendallas]

I am. working on a Mac.

[drdavendallas]

Sorry -- I keep discovering stuff.

Somewhere in my tinkering with the transparency question, I've wiped out my master pages and my sections. 

"All the fields are gone, and the sky is gray ..."

 

[drdavendallas]

OK -- is it possible that that Outer Shadow I am using on all the pictures is functioning as a layer that is throwing off the book publisher's PDF file?