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| ## PDF FAQ Acrobat is a page description language developed by Adobe Systems. It has many enhanced capabilities over PostScript, including graphics and hyperlinking. Acrobat files, ending with a .pdf extension, are often highly compressed relative to PostScript and are platform-independent. The application suite includes acroread, the viewer (which is freely ditributable), distill, which creates pdf files from PostScript source, and exchange (acroexch), which can be used to annotate existing pdf files in various ways. As more and more web publishers use Acrobat PDF instead of scanned images, plain text, postscript, or html for their online documentation, we have seen problems arise from publishers' and end users' unfamiliarity with the tools. Below are some tips and suggestions for creating, viewing, and printing PDF documents. Will my PDF files cause any problems when printed from Athena? What advice can I give my students about viewing/printing PDF files from course web pages? Viewing and Navigation guidelines Printing guidelines Tips for Printing from Acrobat Reader on Athena How to print a PDF file from the command line What guidelines should I follow when generating PDF documents? Optimizing originals TeX/LaTeX originals Word processor or other application originals Converting to PDF Dealing with fonts Why do fonts matter? Q. Will my PDF files cause any problems when printed from Athena? A. Yes, there are some potential problems. We've found that as more and more courses put their course materials up on the web rather than supplying paper copies, the students often end up using public printers to make copies of the documents.. If it is a very large class and the documents they are printing are large, printers can be tied up for hours and other students can't get their work done. Public printing facilities are not meant for such use. We ask instructors and course locker maintainers to carefully consider which documents should be supplied to a class as paper and which are suitable to put on the web. There are two important considerations when putting PDF files on the web: 1. PDF is a compressed format, with files much smaller than PS or other original documents. When you print a PDF file, Acrobat converts it into PostScript and sends the converted file to the printer. Depending on the choices made at each step of the process (creation of the original doc., conversion to PDF, and finally the print command), the PS file is sometimes generated very inefficiently, and becomes much, much larger than it needs to be. When such a file is sent to the printer, it can drastically slow down printing and make server resources unavailable to other users. 2. Printing from the web is not free. While it may be more convenient for you to put up files electronically than to distribute paper copies to students, you should anticipate that anything you make available on the web will be printed at some point by some portion of the class. Printing from Athena costs money (for printing supplies, printer upkeep, server resources, a nd staff support), and is always more expensive per page than photocopying. You should provide hardcopy (either by distributing photocopies in class or through CopyTech or your dept. offices) of any document longer than a few pages, or for use by a class of more than 10 students. In addition, we ask that you post a note your web page(s) to explain that: * PDF files are primarily for online reference, and printed copies are available in class, dept. HQ, or from CopyTech as appropriate. * When printing PDF, students should specify certain settings in addition to following general Athena guidelines. Q. What advice can I give my students about viewing/printing PDF files? A. Viewing and navigation guidelines: Magnification: When viewing a PDF file, the first thing you can do to improve readability is to set the page view. Use the choices at the top of the View menu, or hold down the middle button at the bottom of the window to change from the current magnification (e.g. 100%); be sure to try the "Fit Width" and "Fit Visible" settings as well as specific maginifications. The three "page" icons on the right side of the toolbar at the top of the viewer can also be used to switch between 100%, Fit Page, and Fit Width, respectively. Navigation: You can use the right scroll bar to move around a page or between pages, one page at a time. To jump to a particular page number, use View-->Goto or click on the left button at the bottom of the window (labelled "Page X of Y") and a "go to" dialog box will open where you can type the page number. Printing guidelines: Please advise students to follow the Tips on Printer Etiquette* which are summarized below: Make single, not multiple copies, of what you print. Print only the pages that you need. Preview before you print. Use "lpq" to check the print queue. Know how to kill your print job. Print PDF files as "Level 2" postscript. * See the web page for details #### Tips for Printing from Acrobat Reader on Athena When you go to Print from Acrobat Reader on Athena, you should always check the following settings in the Print dialog box: 1. In the PostScript Options section, choose: * Level 2 PostScript Only * Download Fonts Once These settings substantially reduce the size of the PS files Acrobatproduces for printing, reducing both printing time and demands on print servers. (Level 2 Postscript uses newer features which allocate resources more efficiently, and is supported on all Athena cluster printers. If "download fonts once" is not selected, any font downloading happens at the start of each page, rather than once at the beginnning of the file, which can result in a much larger PS file.) Newer versions of Acrobat Reader will make some of this unnecessary, but for now you may set level 2 as the default by editing your ~/.acrorc file to read: *PSLevel: 2 rather than *PSLevel: 1 2. In the Page Range section, remember that the default will print the entire document. Instead, you can select "From" and fill in start and end pages to print (e.g., "from 4 to 6"). Use this option if you're only interested in a few pages, or to space printing a long document out into smaller jobs to allow others a chance to use a shared printer. Note: the bottom left corner in Acrobat Reader displays thecurrent page and total page count, e.g. "Page 4 of 13". Printing from the command line To print a PDF file from the command line, first convert it to PS as follows, then print the PS file with standard lpr commands. Remember to delete the PS file after printing, to save space; when converting, you can use the -pairs option to save the PS file directly to /tmp (temporary storage) rather than your account, so it won't use up your quota. The following command converts the files and creates filename.ps in the same directory:
    athena% add acro
    athena% acroexch -toPostScript -level2 filename.pdf
Or to specify a different name/path:
    athena% acroexch -toPostScript -level2 -pairs \
    filename.pdf /tmp/newname.ps
To print the file:
    athena% lpr filename.ps [-Pprintername]
Q. Why do fonts matter? A. When Acrobat Reader opens a PDF file, it renders the characters it contains in one of three ways: from fonts installed on the system, from fonts embedded in the PDF file, or by creating substitute fonts. The type of font you use can affect how text in your PDF file appears and prints, and also whether the text is searchable. If the characters in a PDF file display poorly, it is usually due to the choice fonts in the original. In particular, if Acrobat Reader can't find the font installed on the system where it's being displayed, and the font isn't embedded in the PDF file itself, it uses a substitute font which may be a poor approximation to the original (unlike installed and embedded fonts, which should match appearance of the original, on whatever system they are displayed). When creating PDF files, you can avoid font problems and make sure your document'sappearance is preserved cross-platform by taking a few simple steps. Q.What guidelines should I follow when generating PDF documents? A. Generating good-quality PDF files depends upon two things: the characteristics of your originals,and the options you use when converting them to PDF. #### Optimizing original documents #### TeX/LaTeX originals DVIPS generates PS files which contain bitmap fonts for many of the common mathematical fonts. When converted to PDF, these fonts appear dim and pixelated. The solution is to have DVIPS substitute BaKoMa fonts (a free collection of scalableType 1 fonts) instead; the BaKoMa fonts are installed on Athena and can be used by creating a ~/.dvipsrc file consisting of the following line (or adding to existing file):
    p +/afs/athena.mit.edu/contrib/tex-contrib/BaKoMa
    /fontmap.map
If you don't wish to use these substitutions every time you use DVIPS, you can either move aside the .dvipsrc file before running it, or create a file named ~/.config.bakoma consisting of the same line as above and then use the syntax:
    athena% dvips -P bakoma foo.dvi
when you want DVIPS to use the BaKoMa fonts. #### Word Processor (or other application) originals Acrobat Reader includes a set of standard fonts (called the "Base 13" Type 1 fonts) on all platforms:
    Courier (plain, Bold, Italic, Bold Italic)
    Helvetica ((plain, Bold, Oblique, Bold Oblique)
    Times (plain, Bold, Italic, Bold Italic)
    Symbol
These fonts are always available, and should display properly on other systems. Unless you have a need for a particular font (for example, for special symbols), sticking to the Base 13 gives best results. Keep in mind that any other fonts you use may be rendered on other systems by "substitute" fonts (which may display or print poorly), unless you're able to embed them when you convert to a PDF file (see converting to PDF section). Converting to PDF The newer versions of Acrobat Distiller offer different "compatibility options": selecting 2.1-compatibility will allow your PDF files to be viewed by people who are using an Acrobat 2.1 or earlier viewer; selecting 3.0-compatibility will optimize your PDF files, but they can't be viewed by viewers older than 3.0. Dealing with fonts There are three options for handling each font in the file: 1. Embed the font. This "packs" the font into the PDF file itself, so the PDF Reader can recreate it on other systems for display faithful to the original. This makes the PDF file larger, and is not necessary for fonts which are already installed on the system (e.g., the Base 13 Type 1 fonts, which are installed by Acrobat Reader on every system). 2. Subset the font. This embeds just the characters you're using in the PDF file, rather than the entire font. If you are only using a limited number of characters from a nonstandard font, this will take up less space than embedding. Distiller and PDFWriter are configured with a threshold value for subsetting, and will automatically embed the entire font if you specify subsetting when more than the threshold (usually 35%) of the font's characters are used. 3. Don't embed at all. If a font is not embedded, but is installed on the system where the PDF is viewed, it should appear correctly. If it's not installed, it will be rendered by a substitute font, which may look poor on other systems or when printed . How to embed/subset fonts Athena System-wide default is set to subset. If you have custmoized settings, you can specify it manually: athena% add acro athena% distill -subsetfonts on filename.ps For options: athena% distill -help athena% distill -help fonts Mac Distiller: Distiller-->Job Options, Font Embedding tab. (For drag-and-drop, hold down the Command key to bring up the dialog box for specifying settings.) PDFWriter: File-->Page Setup, click fonts button. Older versions may require you to hold down the Ctrl key whicle choosing File-->Page Setup to bring up Fonts. Windows Distiller: Distiller-->Job Options, Font Embedding tab. (For drag-and-drop, hold down the Command key to bring up the dialog box for specifying settings.) PDFWriter: Depending on Windows version and application, choose File-->Print or File-->Printer Setup. Select Acrobat PDFWriter from the Printer menu, click Properties (or Options or Setup), then click Fonts. By default, Distiller and PDFWriter do the following: adds description (doesn't embed) Type 1 fonts, ISO Latin characters (alphabet, numbers, punctuation) embeds Type 1 fonts, non-ISO Latin characters (symbols, ligatures) Type 3 fonts Mac OS bitmap fonts (after converting them to Type 3 bitmaps) converts to bitmap images: will be viewed as graphics, not text Windows outline fonts PCL fonts | Academic Computing | Contact us Last modified: Tues November 24, 1998