Watermarks can do more than just add a faint logo on a background. It won’t serve as tamper protection because it simply acts like a lighter graphic in your presentation. It has no fancy data behind it to protect the presentation’s data.

For example, you give a presentation about publishing. You could weave the history of the printing press into your story or make it the center of your story. Or your company requires you to include the logo on every page, but you don’t want the logo to take away from the story you worked hard to tell.

Start anytime you’re ready to add the watermark. You can use clip art from Microsoft Office or open a picture on your computer. Click Insert and Picture. Then select either Clip Art or From File.

In this example, we’ll use a picture of a printing press. I took out the two objects on the bottom of the image to simplify it. Simplicity works better for watermarks. You can change the images using the techniques covered in Change Clip Art in PowerPoint.

Right-click the image and select Picture tab. Look beneath the Image Control section for Color; and click the down arrow to change it to Washout or Grayscale. Click Preview to see how the image looks. If you wish, play with the Brightness and Contrast sliders. When you’re happy, click OK.

If you need the image on every page, add it to the Slide Master so you don’t have to copy and paste it every time you create a new slide. First, copy the image. Click View, Master, and Slide Master. Paste the image and move it where you want it to appear on the slides.

You may need to resize the image. Select it once and drag any of the circles to make it larger or smaller. Everything looking good? Close Master View. Now the watermark shows on every page.

Should you want the watermark only on specific pages, skip the Slide Master step. Instead, copy and paste the image on the slide where you want it to appear. Move it and resize it as needed.

Open the Drawing toolbar, if not already opened (View, Toolbars, Drawing). Click Draw from the Drawing toolbar, which typically appears on the bottom of PowerPoint. Select Order and Send to Back to put it behind everything. Use Send Backward if you want the image behind one or two things, but not everything.