Issues transferring PowerPoint files containing Prism graphs between Windows and Macintosh.

Why is there a problem?

Transferring Prism files between Prism Windows and Prism Mac is effortless.

Once you put a Prism graph into PowerPoint, it is up to PowerPoint to do the cross-platform conversion and the conversion of PowerPoint files from one platform to the other is sometimes buggy.

The fundamental problem is that Prism Mac copies a graph or layout in PDF format (Prism 4 and earlier used PICT), which is a format that Windows doesn't understand. Prism Windows copies a graph or layout in EMF(old), EMF+ or WMF format (your choice in Preferences), and Macs can't use this format. So PowerPoint has to convert image format you open a PowerPoint file on one platform that was created on the other platform. 

Transfer bitmaps to totally bypass the problem

To avoid this issue altogether, export from Prism as a TIFF or JPG file, and then use the Insert Picture command to insert that into PowerPoint. You can choose whatever resolution you want when exporting from Prism. Since Windows and Mac PowerPoint can both deal with TIFF and JPG files, PowerPoint won't need to do any conversion. It will just work. But bitmaps lose some resolution when stretched, unlike pdf, wmf and emf which encode vectors so lose nothing when stretched. 

Use EMF format when copying from Windows

When you copy a graph (or layout) to the clipboard using Prism Windows (or when you send to PowerPoint Windows), Prism can encode the graph as WMF, EMF(old), or EMF+. You choose in the File tab of Prism Preferences. It might be worth trying all three. EMF(old) seems to work the best. But the problem with EMF(old) is that it can't support anitaliasing, so the graphs don't look quite as good as they do when you use GDI+.

Other tips

• New versions of PowerPoint (2016) are smarter. We know of only one issue with PowerPoint 2016 going from Mac to Windows. Semitransparent (semiopaque) colors are lost (become solid) when a PP file created on a mac are opened on Windows. 
• Opening a PP windows file in Prism Mac seems to work fine if you encode the graphs (layouts) as EMF(old) rather than EMF+ (see below). 
• On the Mac, consider using Apple's Keynote, rather than PowerPoint. It seems that Keynote is more compatible with PowerPoint Windows (at least older versions) than is PowerPoint mac. 
• If you are having trouble with a slide that shows a Prism layout, try copying the graphs one by one. We don't have any firm information, but it sometimes seems that conversion works better when individual graphs are pasted into PowerPoint than when entire layouts are pasted. 
• When you copy and paste Prism graphs into PowerPoint using Windows (or use the send-to-PowerPoint toolbar button), you embed a Prism project into the PowerPoint file. PowerPoint Mac seems to have a particular problem dealing with these objects. Of course, you can't double-click to open the Prism file (the Mac does not support this kind of Object Linking and Embedding). And the presence of the object can affect display of vertical text. There is a simple workaround. Select the graph in PowerPoint Mac, and ungroup it (a choice on the Draw menu, usually accessed from a button at the bottom --yes the bottom-- of the PowerPoint window). Then regroup. This process of ungrouping and then regrouping gets rid of the Prism object and leaves just a picture. In the process, somehow the vertical text is usually fixed.

If you still use Prism 4

• Prism 4 Mac offers two choices (in preferences dialog) for how fonts are encoded. If one method gives you trouble, try the other. Prism 5 copies as PDF rather than PICT, so does not offer these choices.
• With Prism 4, the problem is often with theY-axis title. One solution is to leave out the Y-axis title in Prism, and create it within PowerPoint. Insert a text box, type the title, then rotate the box (choose "Format... Text Box...", select the "Size" tab, and assign a value in the "Rotation" box).