Abstract: An inexpensive, lightweight reflective panel for solar-thermal collector modules of the type including a parabolic reflector for reflecting incident solar radiation onto a fluid carrying conduit positioned along the focal axis of the reflector. A rigid, waterproof, honeycomb panel formed from paper and having a uniform thickness of parabolic shape supports a reflective material. Glass fiber cloth adhered to the outer panel surfaces adds to the panel's strength and rigidity. An adjustable support system suspends the reflective panel from the fluid carrying conduit and provides a means of adjusting panel curvature to precisely obtain the required parabolic shape.Methods of forming the panels are described which permit the panels to be formed at or near the site of their installation to obviate shipping problems and expense.