Shapes Print with Unexpected Borders

If you print your PowerPoint slides with either the Grayscale or Pure Black & White options selected in the Print dialog box, you may find that objects you expected to be invisible print with a black outline. For example, if you've used a rectangle the same color as the background to block out another object on the slide, the rectangle will show up as an unfilled but outlined rectangle on your printouts.
If you run into this, first try printing the problem page again, but deselect the options Grayscale and/or Pure Black & White. If that doesn't help, try customizing the way the object prints in Black and White View. Click Black And White on the View menu; PowerPoint displays your presentation as it will print it to a black and white printer. Right-click the object that you're having trouble with, choose Black And White from the context menu, then click White.
Verify that the object is displayed on screen the way you want to print. If not, try one of the other Black And White options.
Note that this affects ONLY the way PowerPoint prints your presentation to black and white printers. It won't affect what you get when you display the presentation as a screen show or print to a color printer.