Watermarking, a long-standing technique for applying security layers to documents, simply involves adding an overlay to the image. This prevent others from illicitly copying the image or passing it off as their own property. Watermark your own pictures with a few clicks in Microsoft Paint, a free basic graphics program included in all Windows operating systems.
Open Paint. Click the Paint button in the top-left corner of the workspace. Click "Open." Browse to and double-click the picture that you want to watermark. The image appears on the Paint canvas.
Click one of the colored squares in the "Colors" section of the toolbar. Choose black, gray, white or another color that will stand out from the colors of the picture.
Click the text icon, which looks like an "A," in the "Tools" section. Click the part of the image on which you want to place the watermark. Choose a font and text size.
Type the text of the watermark into the text box. Common watermarks include "Copyright," "Property of..." and the date.
Resize and reposition the text box to stretch across the picture by grabbing the top-left corner and pulling it into place.
Click the Paint button again. Click "Save As." Type a new name for the picture -- so as not to overwrite the original -- and click the "Save" button.