Can you attach indesign file of just these 2 pages.
I think what you are seeing is a transparency artifact that has the effect of making text on pages look bolder than text on pages without transparency. The effect is visible in ID, and in PDF on screen or when printed on low-resolution devices, but generally is not seen in high-resolution output on a press. This is a well-known issue in ID, and there's nothing you can do about it other than make sure that all pages have transparency if any page will have it and the effect is bothersome.
But I noticed another issue that I can't as easily explain when shifting between the images. There seems to be more space between the top line of text and the empty rectangles below it in the bolder version than there is in the lighter version. Is that something you've done?
Yeah this is something i've done, because the text above we don't see here is bigger. But it sure isn't because of this, as I have said I have the same probleme on lots of pages, and it does it for the whole content of the page, including master's elements or unique elements. Only objetcs where there isn't problem is on imported photos... Also, please note that i see the problem on high quality offset industrial printers, the one which will be used to print the thousand of pages in a few days.
Ok i just tried a lot of things to upload the pages here. I went through modifications and all, to send you two fake pages. At the end of modifications the problem was gone... So by watching every step of the modifications i made i identified the problem :
The lines and fonts get thin when i put pictures on the spread (it gets thin if i put pictures on the facing page also) and it's getting back in bold when i delete them. Now that i know this, i can see that indeed every pages with pictures are the pages with thin lines... the thing is, i will have to put pictures on every pages.
Pictures are psd in CMYK japan coated if this can help.
I'll let you know if i find the solution, in the meantime thank you if you have any tip
If i don't find anything i may just make the font a bit bolder, but I don't really like this solution because text placement is really precise in some pages.
Thanks a lot for your answers!
Ok then, i found the problem...
So please note to everyone reading this, don't use psd with dynamic objetcs in your indesign projects... Because that was the problem^^ I flattened all my psd and problem is gone. Thanks again!