How to make pdf with many duotones smaller

[Gerald_Singelmann@adobeforums.com]

Lydia,

JPEG works only (properly) for RGB and Grey.
When you try to jpeg a CMYK image you get 4 jpegged greyscales sandwiched (a lot larger than the according RGB).
When you try to jpeg a duotone you do not get a jpeg at all but a zipped image.

So your only way to get small files for "have a look at this" is to convert them to rgb before compressing.
The way to do this it seems is to create a distiller setting with "convert to sRGB" in the colour section and "compress to jpeg" in the image section.
It seems this cannot be done by export since InDesign always tries to honour/preserve your duotone.

[tman@adobeforums.com]

this may seem like a stupid question (you didn't say how you are making your pdf file from Indesign) have you tried 'export as PDF with 'export setting' at the default 'smallest file size'?

[Lydiap@adobeforums.com]

Hi guys,

At the moment, I do distill the files. So I write a postscipt file from indesign and then convert it into pdf through distiller. I export a RGB postscript and then distill using RGB. (I also have used the 'smallest file size' setting (in distiller) but have adjusted it to make it even smaller and lower res.

Any other thoughts?

PS: That was interesting about the jpeg of a duotone just being a zipped image when coming straight through the 'adobe pdf presets' 'smallest file size'. That now explains to me why I've always found this too big.

[J.I.M.@adobeforums.com]

This will help a bit:
Make a copy of your ID file, and in that copy convert the Spot Duotone colours to Process. Then in PDF Export Presets, export to "smallest file size" with default destination colour as sRGB.

[Lydiap@adobeforums.com]

Hi J.I.M. I've done that procedure, but it actually makes the file slightly bigger than the distilling technique (not by much though, and if I was after a quickie way that would be wonderful so I will remeber that). Has anyone found any other techniques. I think it's the problem is more based in the dutone photos.

For instance with this same file if I take all the photos into photoshop and convert them to rgb and place them back again, the file size of the pdf i make from this file is half that of any of the techniques we've used in this discussion. So any other thoughts or comments on this would be gratefully apprieciated!.

Cheers

[Peter_Truskier@adobeforums.com]

Lydia,

Do I understand correctly that you want a lo-res PDF?

If so, how about making the duotone images inaccessible to InDesign (either by dismounting the volume on which they are located, or by stuffing/zipping them and deleting the actual image files)?

If you do that, InDesign will alert you about missing images, but then use it's internalized previews (72 ppi, RGB) for export or print.

[Lydiap@adobeforums.com]

What a clever idea!

I've done that and that has made the file size the same as if it was rgb.

I guess I will be doing this in future, it's a shame that there isn't a function to convert these duotones properly in indesign though.

cheers and thanks everyone for your help!

[Chris_Atkin@adobeforums.com]

My experience with duotones has been the same, large PDF files. It is as if Distiller could not or would not compress the .eps. But those were Quark days. So for PDFs we would convert the dutone to 4-color, or bring in a BW tiff and create a fake duotone. This would be for proofing only of course...

But now that we have been living in InDesign for the past 2 years and only place .psd files from photoshop, I have no worries when saving out Hi Rez PDFs, let alone low rez. The file size is what it should be.

I am sure one day soon we will no longer be able to save out .eps files. I wonder what Quark will do then. HA!

Give a duotone .psd a try.