Parallel Line Development is a course that teaches students essential techniques for developing flat 2D patterns from 3D objects with parallel generating lines. Designed for drafting, sheet metal, HVAC, and fabrication students, this course covers the fundamental principles, step-by-step procedures, and real-world applications of parallel line development for right and oblique cylinders, prisms, and transition pieces. Participants will learn to create accurate stretch-out patterns from orthographic drawings, determine true lengths, and apply best practices to minimize errors.