Step 1:

Open PowerPoint and select a slide or master slide in a presentation. Click the "Insert" menu and then select the type of picture you want to use from the Images group. If possible, select a line drawing. There are thousands of clip art images available under the Online Pictures option. Full-color photos may not always give you the best results for a watermark.

Step 2:

Resize the image if needed by dragging any corner handle. Pressing the "Shift" key while dragging retains the aspect ratio. Click the "Format" tab under Drawing Tools, then click the "Color" option in the Adjust group.

Step 3:

Scroll through the available color variations to select a pale, light image. Scroll to the bottom to see more variations. Clicking "Set Transparent Color" can remove a color from the image. Although you don't need it for this project, if you select "Picture Color Options" from the bottom menu, you can more precisely control the image colors.

Step 4:

Click "Corrections" under the Picture Tools Format tab. This gives you the ability to make the picture brighter and to select an appropriate contrast.

Step 5:

Select a pale, bright image from the available images, then scroll to the bottom. Click the "Picture Corrections Options" link at the bottom. Your new variation appears on the slide with a Format Picture menu on the right.

Step 6:

Drag the "Brightness" and "Contrast" sliders to make your image a pale watermark. The settings will vary depending on the image you are using.

Step 7:

Click the Picture Tools "Format" menu once again, then click the "Send Backward" option in the Arrange group. Click "Send Backward" as many times as you need to put the watermark below the other objects. To put the watermark at the back in one step, click the Send Backward "Arrow" and select "Send to Back."

Step 8:

Drag the watermark to your preferred location on the slide. Save the presentation or continue working on it.

Step 1:

Select a slide or master slide where you want a text-based watermark to appear. Click the "Insert" menu and select "Text Box."

Step 2:

Drag the cursor on the slide to create a text box, then type the words you want to use. Double-click the text to highlight it, then use the formatting options that appear over the text to modify it as needed. Move or rotate the text box if desired by dragging the handles that appear on its border.

Step 3:

Click the "Format" tab under Drawing Tools, then select the "Text Fill" option. This is the first of three small As in the Word Art Styles group. Select a color that is slightly darker than the slide's background. If the background is white, select a light gray. Select "More Fill Colors" if the color you want isn't available in the palette.