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What Kind of File Do You Need

File format is a bugaboo for lots of folks: how do you tell someone what format you need? Here are some common situations and the information you need for most cases. Please feel free to call and ask for additional help.

In the Windows environment there is a period followed by three letters at the end of the file name called the "extension". This tells Windows what program can read the file. Realize that you can't change the file type just by changing its name. You have to have saved the file in the format you want; the three letter extension just makes reading the file easier. On a Mac the file type is stored inside the file so you need to be sure to tell someone what kind of file you are giving them. If you work on a Mac and are saving the file for someone in Windows, be sure to give the file the proper period and three letter ending for the file type you are saving:

Word: .DOC (or save in "rich text format" .RTF or "ascii" .TXT to cope with unknown word processors)

PageMaker 6 or 6.5: .PM6 or .P65

Excel: .XLS (or save as "tab separated text" .TXT or "comma separated values" .CSV to import into Lotus or other spreadsheets or databases).

PowerPoint: .PPT

Photoshop: .PSD (or save as types: .TIF, .JPG, .GIF, .BMP)

Adobe Illustrator (.AI) or Macromedia Freehand (.FH7): if you don't know how the file will be used, it's best to save it as "encapsulated PostScript", .EPS, if it is printing to a PostScript printer; convert to a Windows Metafile or Enhanced Metafile, .WMF or .EMF, if not.

How do I choose the correct graphics file type? Graphics files come in two types: Bit-Mapped and Vectored:

Bit-mapped images (this includes scanned, raster, TIF, paint, PCX, GIF, JPG, BMP) are resolution dependent. If you make them bigger, they get jaggy. If you have enough information in the file to print it large, the file is huge. For example a 2 inch square black and white scan of a line art image to print on a 600 dpi laser printer needs to be (2 x 2) square inches x (600 x 600) bits per square inch = 180K byte file. A photo (gray scale) file is 8 times this or 1.44 MB (this is about what a high density 3.5 inch floppy holds). Making the image 4 inches square results in a file not just twice as large but 4 times larger. Many of the above file formats like TIF, JPG and GIF compress the file somewhat so you don't really get this size file until it gets sent to the printer. This is part of the reason some graphics take so long to print. TIF is the preferred format for high resolution printing. JPG is best for web photos and GIF for other web graphics. PCX and BMP are editable in Windows Paint but not much used otherwise.

Vectored files (.EPS, .WMF,.EMF, .DXF) are not resolution dependent: if you make them bigger they don't get jaggy unless they contain an included bit-mapped file and then only the bit-mapped part gets jaggy. Vectored files are a mathematical description (remember vectors from your geometry class?) of the graphic. They are not generally very large files. You can usually recognize vectored graphics by their hard edges: a pen and ink rather than a watercolor look. You can scan a piece of line art and run it through Adobe Streamline or Corel Trace to convert it from bit-mapped to vectored. This is often done to create resolution independent files for business logos. Which type of file you save it as depends on how you are going to use it: .EPS is for PostScript printers (unless you use GhostView), .WMF and .EMF are great for non-Postscript Windows printers but is not very useful in the Mac environment (there are exceptions), .DXF is for CAD (computer aided drafting) and is often used in vinyl-sign making.

How do I deal with a file someone sends me as an e-mail attachment? Just double clicking on the file doesn't work in many cases. Save the attached file to your hard drive. To do this in many, but not all e-mail packaes, try right clicking (Windows) or holding the mouse down without moving it (Mac) and choosing save file to disk from the menu that appears. Hopefully the sender will tell you what kind of file it is. Open that program or a program which reads that file type and then go to the file menu of that program and open the file from where you saved it.

How do I e-mail a word processing file to someone else? Hopefully you know what program they want to use it in. See Word, above, for file saving tips. If you have an early version of Microsoft Office 97, go the Microsoft web site ( or call their customer support and get SR1 (service release 1; get SR2 as well to fix other things) for the filters to read and save as previous versions of Word as well as fixing some other bugs. You can just open your word processor, copy the text to the clipboard, open your e-mail message program and paste in the text. To attach a file instead, look for the paper clip icon and use it to link to the file before sending.

How do I make a logo file for my client to use in Word for Windows if I'm on a Mac? You created the file in a vector type illustration program, converted all fonts to paths to avoid problems and then saved it as an .EPS but your client doesn't have a PostScript printer and doesn't have GhostView (freeware: If you (or your client) don't have a program which saves in WMF (or try EMF in newer versions of FreeHand and Illustrator) but you do have Word 98 you may be in luck. Open a new word file, insert the EPS graphic. Double click on the graphic. The draw editor should come up and ask if you wish to convert the graphic to Word format. Say yes. If the graphic isn't too complex, it will make a WMF file. Don't bother trying to save it out, just give your client the word file (they should have Word 97 or later). Remember to use a .DOC extension on the file name. Or call us and discuss having us convert your file for you.

How do I make a "postscript dump file" ? This is what most print shops prefer (more recently PDF -- see below). It contains all the fonts and settings and they don't even have to have the program. However, if you don't do it exactly correctly, they can't print it and they can't open the file to make a change. You have to install the driver for their printer, choose all the correct options and then choose "print to file". The details get tricky, the print shop often has a handout. Call if you need help. Better yet, before you get started, ask the print shop what program and fonts to use so you can just bring them a regular file.

How do I distribute an exact copy, format and all, to someone who doesn't have my software program? The IRS has this problem with its forms. They use Adobe Acrobat .PDF files. The reader is free ( and you buy the "Distiller" to create the files (or it comes free with many Adobe products). The other choice is a scan or fax file which is bit-mapped and large.

Give us a call at 206-523-0872 if you have further questions.

copyright 1998 Karen Seymour

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