A comp card (also called composite card, zed card, often misspelled sed card and set card) is a marketing tool for actors and especially models. They serve as their portfolio and business card.
A comp card typically contains a minimum two pictures — cover page with full size portrait and second page with a selection of representative shots from the portfolio — and the model's basic stats — typically height, weight, three sizes (bust, waist, hips), shoe size, eye and hair color, nationality and contact information — printed on both sides of an 8.5" x 5.5" piece of card stock (12 pt stock) (US) or A5 (Europe, Asia).
Comp cards have been around for many years as the essential marketing tool for a model and are likely to retain this standing because they are an inexpensive way to effectively and professionally showcase a model's ability. Composite cards are used on three major levels—they are used by models, agents and the agent's clients.