Which format is best for exporting a Prism graph?
Are you sure you want to export?
If your goal is to send graphs to a colleague who doesn't own Prism, consider sending a Prism file. He or she can then open the file using Prism itself, the free Prism trial (which expires in 30 days but then becomes a free Prism viewer that never expires).
If your goal is to place graphs into a Word document or PowerPoint presentation, you can copy-and-paste or use the one-click send buttons rather than exporting. There are some settings in the File & Printer tab of the Edit/Preferences dialog that will affect the result and whether or not you will paste your graph as a Prism object or a picture. Read more about copy and paste settings.
Background color
Within Prism, there is no distinction between having a clear background and a white background. When you paste or export a Prism graph into another program, a clear background will let colors and objects show through, so Clear is not the same as White. The problem is that not all export formats support the concept of transparency, and Prism doesn't support all formats. The .jpg and .bmp formats simply have no concept of a clear background, so those file formats simply don't allow for the possibility of clear backgrounds. Read more about exporting or copying and pasting with transparent backgrounds.
Vector Formats (Recommended for Quality)
PDF (Recommended)
Prism 5 and later can export graphs and layouts as PDF files. This is built into the Export command. You don't need to "print" to a pdf file, or install any other software. When exporting several graphs or layouts, you can choose to export all to one PDF file or to create a PDF file for each sheet. Prism's PDF files include vectors and fonts (not bitmaps), so there is no loss of quality.
PDF is generally the best format when you can use it. The files are compact, sharp, and can be scaled to any size without quality loss. PDF is the preferred format for transferring images between Mac programs, though fewer Windows programs and journals accept them.
Advantages:
- Vector-based with infinite scalability
- Supports transparency
- Compact file size
- Universal compatibility for viewing
- Can combine multiple graphs in one file
Best for: Academic presentations, Mac workflows, high-quality printing, archival purposes
SVG (Scalable Vector Graphics)
SVG is a modern web-standard vector format that offers excellent scalability and web compatibility. Prism can import SVG files, and Prism versions 10.6 and newer support SVG export.
Advantages:
- True vector format with infinite scalability
- Excellent web browser compatibility
- Supports transparency and gradients
- Text remains selectable and searchable
- Smaller file sizes than most bitmap formats
- Can be edited with web technologies or vector graphics software
Best for: Web publications, online presentations, modern publishing workflows, interactive documents
Note: SVG files can be easily converted to other formats if needed, and are increasingly accepted by academic journals for online publication.
EPS (Encapsulated PostScript)
Prism can export to the EPS format. These EPS files use vectors and fonts. They don't just put an EPS wrapper around a bitmap file. Prism exports EPS files by encoding fonts with the "Type 42" format. Most newer programs that import EPS files expect fonts to be encoded like this. Some programs that use older technology cannot understand this font format and will not be able to import the EPS files that Prism exports. There is an option to include or not include fonts in the file. If you don't include fonts, the file will be smaller, but the importing computer must have the same fonts for the imported file to look correct.
Note about fonts: Prism Windows offers an option to convert fonts to outlines when exporting to an EPS file. Prism Mac always converts fonts to outlines.
Best for: Traditional publishing workflows, Adobe Illustrator, journals that specifically request EPS
EMF/WMF (Windows only)
Windows Metafile (.WMF) and Extended metafile (.EMF) files contain vector and font instructions for how to draw the graph. This means you can resize the image (in another program) with no loss of quality.
WMF is an ancient format; EMF is old, and EMF+ is the newest. So generally EMF+ is the best format. But not always. You may need to experiment to see which format works best for your needs.
Your only option is whether to include the page background. Omit the background color if you will apply a fancier (e.g., gradient) background in another program.
Best for: Windows-only workflows, Microsoft Office integration
Bitmap Formats
TIFF (Recommended for Publication)
Many journals ask you to submit your figures as .TIF files. This is a bit-map format, which means that your graph or layout is turned into a collection of dots. You need to choose resolution, color model, and size.
Resolution: Computer screens display images at about 100 dpi. Computer printers generally print at 300-600 dpi, and publications are generally printed at 1200 dpi. Journals typically ask for a file at 1200 dots per inch (dpi), the highest resolution that Prism offers.
Color models: Choose between RGB (designed for computer monitors or projectors) or CMYK (designed for printing). If you are submitting to a journal, follow their instructions. If in doubt, choose RGB.
Size considerations: Typically, graphs and layouts in Prism projects are much larger than publication size. If you ask for a graph at 1200 dpi at the actual size in Prism, you will end up with either a huge file or an out-of-memory error message. Avoid this problem by specifying the publication size. For example, if your graph is 6 inches wide but you will publish it at 2 inches wide, reducing to 2 inches will create a file one-ninth as large.
Compression: With TIF format, and no other, Prism lets you choose to compress the file. The advantage of compressing is that the file is smaller. The disadvantage is that compressed TIF files might be less compatible with other programs.
Best for: Journal submission, high-resolution printing, archival storage
PNG
The .PNG format is great for posting on web sites and offers good compression with no quality loss (unlike JPEG). PNG supports transparency, making it useful for presentations and web use. However, these files typically have too little resolution for submission to printed journals when exported at standard web resolutions.
Best for: Web use, presentations, screenshots, images with transparency needs
JPEG
The .JPG format is designed for photographs with gradients of similar colors. It is not a particularly good format for exporting line art and graphs. Prism offers this choice because some journals insist on it, but we recommend that you use the .TIF, PDF, SVG, or EPS formats when possible. The only advantage of .JPG is that the files are smaller.
Most programs that export to the .JPG format give you a choice of compression. If you compress more, the files will be smaller but the resulting image won't be as sharp. Prism gives you no choice. It only exports to the .JPG format with the least possible compression, making larger files but sharper images.
Note: Prism mistakenly offers the option of "monochrome, no grays" when exporting to JPEG, but this option does not work. If you want a monochrome export, use TIFF not JPEG.
Best for: Only when specifically required by journals or when file size is critical
Legacy and Specialty Formats
PICT (Obsolete)
PICT files are a Mac-only format that is now obsolete. Prism 4 exported PICT files that contained vector and font instructions for how to draw the graph. This means you can resize the image (in another program) with no loss of quality. Apple took away the ability to make this kind of file. Prism 5 can export a PICT file, but this is simply a bitmap with a PICT name.
BMP and PCX
Prism Windows can also export to the BMP or PCX format, but these are older formats and there is really no reason to choose them.
Quick Recommendations by Use Case
For journal submission: TIFF at 1200 dpi, or ask about SVG/PDF acceptance For web/online use: SVG (preferred) or PNG For presentations: PDF, SVG, or PNG with transparency For Adobe Illustrator: PDF or EPS For Microsoft Office: EMF/WMF (Windows) or PDF For maximum compatibility: PDF or TIFF For smallest file size: SVG (vector) or JPEG (bitmap, with quality loss) For future-proofing: PDF or SVG
Notes on Transparency
The TIF, PNG, PDF, WMF (Windows only) and EMF (Windows only) formats allow you to choose a transparent (clear) background. With Prism Mac, but not Prism Windows, you can choose a clear background with EPS export. SVG also supports transparency. The .JPG and BMP formats simply have no concept of a clear background, so those file formats simply don't allow for the possibility of clear backgrounds.