PDF conversions with css.

PNG isn't supported, unless they changed that in version 7 I am not familiar with. The only way I can get PNGs to show up, and CSS defined styles, is by printing the webpage from the browser through PDFwriter or the Distiller. That still doesn't give you much room for control though. PNGs converted by the Distiller can look crap, as they're meant to be seen on a screen, and not on paper.

I'm not sure what your conversion workflow is, and I freely admit that this sounds very silly, but have you considered creating a print stylesheet from which you would produce the PDFs? You could reduce your complexity-related formating errors, and as a bonus maybe produce a layout more sensible for print than what you've got already. Also, (and again, I'm not sure how you're doing this,) if you're using Firefox or Mozilla's printing functionality at any point in this process, you should know that the Gecko engine is notorious for its confused printing of complex webpages. If you are using a Gecko-based browser, you might want to consider doing this particular task in Opera, Safari, or (sigh) IE.

On my second re-reading of the question, I began to understand that the question is really about PNGs and background images in the PDF (not the HTML). Uh, as for background images, they are commonly omitted by browsers when printing, unless you explicitly ask to print them. More generally, I think that we might need more detail as to your workflow here. Like for instance, what browser are your printing from? What settings? What PDF driver are you printing to to do the conversion? What settings on that end? too many unknowns. W/o more detail, you will just get dumb guesses (like my guess about background images)

Uh, as for background images, they are commonly omitted by browsers when printing, unless you explicitly ask to print them. (Slight Aside) And how is that done? In my print style sheets I have to substitute the background of say a particular div id="whatever" with an img tag within the div. For a logo for example. I haven't seen how you can get background images that are specified in the style definition to print.

juiceCake: http://www.google.com/search?q=printing%20background%20images (g). It's browser-specific, somewhere in print options. You can never FORCE the user-agent to do anything, and background images are one thing that they decided at some point to default to off (for legibility and ink reasons). mystyk, what about (since you are already mucking around in PHP) generating the PDF on the server-side? rather than relying on the vagaries of client-side printing (if that is what you are indeed doing)

Ok, I'll clarify all this a bit. I'm the Company (and for all intents and purposes the Battalion) Publications Officer. My job is to archive all unclassified (and some classified) documents produced into a .pdf form for eventual submittal to Brigade HQ. Every single one has to be in pdf, even if it makes no sense (like .ppt files. Army. Go figure). When I get a doc, ppt, xls, etc. it's pretty easy, but some of the material is web-published (like newsletters) and has to be converted directly. I helped write the php, but trying to produce pdf from extensively css controlled sites works miserably when you use the pdf plugins for php. I need them to look proper, and messing with the print options on my side is really the only way I can be sure about, and tweak, the display. I'll use that specific newsletter example for further illustration, as it's the only web conversion I'm doing that has all three issues. The site uses a background, and it's placed in the div fixed & centered. My print options have backgrounds supported, but only bgcolor shows up in the pdf, not bgimage. It has a picture on the top, which is actually a gif (but I have a png version too) placed atop a jpg. It converts the clear to white when in the pdf. Something about the css makes it only print the first page, and I think it might be related to the fixed status of the background, but I'm shooting in the dark on this one. When I hand-coded the format using tables in order to test, the first two problems remained but the printing only one page issue vanished. It's a bit impractical for me to re-code by hand 150+ documents (plus future ones too) in the next month or two.

Why are you not just opening the page in Acrobat Pro, later versions of which use the Opera rendering engine?