Lay a piece of lightweight tulle or nylon-blend fabric flat on your work surface. Lay the wood frame on top. Allow a few inches of fabric on all sides of the frame.
Pull one side of fabric over the frame edge and apply decoupage medium or a glue and water mixture over it. Be careful not to drip on the center of the fabric. Press the fabric to the frame and let dry five minutes.
Pull the fabric tight on the opposite side. Apply decoupage medium to hold; let dry. Repeat on other two sides. Make sure the screen is stretched taut. Trim excess fabric when dry.
Flip the frame so the screen faces up. Apply the glue mixture around the outer edges, as well as about 1-1/2 to 2 inches in on the screen. Let dry.
Create a design by printing clip art or drawing a simple doodle on paper. Set the design on the work surface and position the screen facedown on top. Lightly trace using a soft lead pencil.
Flip the frame to face up. Brush decoupage medium onto the areas of your design you don't want to be printed. Cover thoroughly, as paint will go through any small holes.
Place the pillow cover on a level work surface. Smooth or iron wrinkles. Position the frame screen-side down on top of the fabric. Pour ink along the upper inside of the screen above the pattern. Pull the ink down with a squeegee held at an angle. Lift the screen and let dry.