In this photo you can see the finished quarter round return or end cap.
How to Install Shoe Molding or Quarter-Round and Cut a Return: Cut Second Angled Piece
How To Decorate Your Walls with Molding | pink little notebook
Discount Glass Tile Store - Handcrafted - Dove Gray 5/8" x 6" Quarter Round Molding Highland Park , $3.98 (http://www.discountglasstilestore.com/handcrafted-dove-gray-5-8-x-6-quarter-round-molding-highland-park/)
An example of wood-colored quarter round molding.
Whisper White Quarter Round 5/8x6 Molding
Highland Park Quarter Round Molding - Morning Fog 5/8" x 6"
Zamma Santos Mahogany 3/4 in. Thick x 3/4 in. Wide x 94 in. Length Wood Quarter Round Molding-01400701942506 - The Home Depot