In the video, a person is seen using a tool to cut through a piece of fabric. The fabric appears to be a dark color, possibly black or navy blue. The tool being used is a hot knife, which is a type of soldering iron with a flat tip. The person is carefully applying the hot knife to the fabric, creating a precise cut. The fabric is held taut by the person's other hand, ensuring a straight line. The hot knife is moved slowly and steadily, allowing the fabric to melt and fuse together as it cuts through. The video provides a close-up view of the cutting process, showing the details of the fabric's texture and the melting of the material as it is cut.