Creating your own PDFs used to require purchasing a PDF-creator like Adobe Acrobat. With PrimoPDF and doPDF, though, all that's required is a program with a print function. Interestingly, while both Do and Primo do the same thing, one is stripped-down and simple, while the other adds an extra step and some extra features to attract users.
DoPDF is the more basic of the two programs. It's utterly bereft of features beyond its main function: to let users create PDF documents from within any program using the native Print option. Along with whatever printer you've got hooked up that shows up in the Print dialog box, doPDF adds an eponymous option. Select it, hit print, and you get the chance to change the name of the PDF you're creating. Hit enter and the PDF gets created, then automatically opens for you to proofread it.
Lacking any customization features and the control panel to manage them, doPDF is definitely meant for fast PDF creation with a minimum of fuss. However, not all PDFs are created equal, and that's where PrimoPDF comes in.
Primo uses the same mechanism to create PDFs as Do does: It lets users create PDFs via the Print function of most--if not all--programs that have a print option. However, the addition of extra features should appeal to more advanced users who need their PDFs to be of higher-than-average quality.
Whereas doPDF just gives a simple output dialog box for altering the name and saving location of the PDF, Primo lets users choose from four preset resolution levels plus a custom-set fifth one. The four others optimize the PDF for screen use, Web use, eBook, or prepress. The variations between them adjust image quality more than anything else, because that will instantly jack up or shrink the size of the PDF.
Three features within Primo's Options window should make it truly appealing to advanced users. Users can edit the document properties, which include adding meta info like title, author, subject, and keywords. You can also set two security levels, one for opening the document and another for making changes to it. The app comes with the ability to wrap up your PDF in 40-bit or 128-bit encryption. You can even specify access solely for text-reading programs for the visually impaired. The third feature lets users specify which program opens the PDF, even overriding your system's default PDF reader setting.
However, all these extras come with a cost: PrimoPDF uses about 40MB of RAM when running. That's not a major concern, except it's about 40 times what doPDF consumes. If none of Primo's features sound useful, doPDF is probably the PDF converter you want to use. But for any project requiring a bit more finesse, there's no reason you shouldn't be using PrimoPDF.