Exporting and copying graphs (or layouts) with clear backgrounds.
Why make a background clear (transparent)?
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.
Distinguish background color from plotting area color
Prism lets you set two separate colors for the background of a graph. What Prism calls the background is the color of the 'page'. The plotting area color is the background color within the plotting area defined by the axes. Both can be set by right clicking (control-click for mac) on the graph, or by dropping the color wheel icon. Layouts, of course, only have the page background property.
Prism Windows
You can choose a clear background when you export in PDF, EMF or WMF formats. This choice is in the Exporting options part of the Export Graph dialog, where you can choose to include a background color or omit it (make clear).
Prism 5.02 includes a new option in the lower right of the File tab of the Preferences dialog that determines whether Prism copies graphs and layouts with a clear background or with the background color selected in Prism.
If you paste into PowerPoint 2007, and want to paste an OLE object rather than a picture, beware of this bug in PowerPoint.
Rather than copy-and-paste, consider using the Send-to-Powerpoint button. It will always copy the background color, and also send a message to PowerPoint to change the background color of the entire slide to match.
On the bottom of the File&Printer tab of Preferences in Prism 6, there is an option about how to copy graph (and layout) backgrounds. Set it either to copy the background color you set, or to copy with a clear background.
Prism Mac
Prism, since 5.0b, can export clear backgrounds and plotting areas to PDF, TIFF, and EPS format.
When you copy and paste, Prism puts two versions onto the clipboard. The PDF version supports transparent background and plotting area. Whether the background is clear or not depends on an option you set in Prism's Preference dialog (bottom of File&Printer tab). That preference is a new choice in Prism 5.0b.
When you paste into Pages, Keynote, or Word 2008, the pdf version will paste.
When you paste into PowerPoint 2008-2010 (due to a Microsoft bug, fixed in PowerPoint 2013), the Paste command will paste a bitmap (that does not support clear backgrounds). To avoid this problem, use Edit...Paste Special and choose to paste the PDF version of the graph. Better, rather than copy-paste, use the Send-to-PowerPoint button (added in Prism 5.0b). When you send a graph to PowerPoint that way, clear backgrounds are supported.
Older version of Office and iWork cannot import or paste pdf images, but can only import or paste bitmap pictures, which do not allow the concept of clear backgrounds. Prism (starting wth version 5) cannot create the old vector-font based PICT files (which do allow clear backgrounds) because this format is no longer supported by Apple.
Prism 4 Windows
Prism 4 for Windows includes an option when exporting a file in tif or jpeg format, to include the background color in the exported file or to make it "clear." The clear option does not, in fact, produce a transparent background. Instead, it converts the background to white.
When you copy a Prism graph to the clipboard, the background color is not copied but rather is made clear.
Prism 4 Mac
Prism 4.0c offers an option to make background clear when you export in PICT format, and always makes the background clear when copying to the clipboard.
Early releases of Prism 3
There are some problems with creating gif files with transparent backgrounds with early releases of Prism 3. To create a gif file, Prism has to reduce the color count to 256. After doing so, the background color sometimes changes and Prism is then unable to convert the background to transparent. You can work around this limitation by switching your display to show only 256 colors. Do this by clicking Start.. Settings.. Control panel.. Display.. Settings.