# Pile-up > Carpet fibers that bunch or lift at the edges of a sample and show up badly under raking light. Category: Photography techniques. Pile-up is a capture defect in carpet photography: fibers at the edges of a sample bunch, lift or curl instead of lying flat, typically after a deep-pile rug has been rolled. It is best prevented by preparing the pile before capture. ## How PhotoRobot uses it Under [raking light](https://www.photorobot.com/glossary/raking-light) it is very visible. The fix is to stop, smooth the pile along its natural direction, let the fibers relax for a minute or so and capture again. Covered in the [Carpet Photography Specialist](https://www.photorobot.com/glossary/carpet-photography-specialist) track. ## Related terms - [Raking light](https://www.photorobot.com/glossary/raking-light): Light at a low angle across a surface that reveals texture through long shadows. - [Carousel 3000](https://www.photorobot.com/glossary/carousel-3000): PhotoRobot 3 m rotating platform for cars, furniture and other large objects of up to 2000 kg. - [Carpet Photography Specialist](https://www.photorobot.com/glossary/carpet-photography-specialist): The PhotoRobot Academy specialty track for the Carpet Studio built on the Carousel.