Question

Predicting Type of Reflection
A photo with a blue background and white squiggles.
This is a microscopic view of paper. What type of reflection occurs when light strikes paper? Justify your answer.

Answer 1

Diffuse (scattering) reflection. Paper is made of randomly oriented fibers with air gaps and an uneven surface at the microscopic scale, so incoming light is scattered in many directions rather than being reflected in a single mirror-like direction. Because of this multiple/volume scattering across all visible wavelengths, untreated paper looks white; printed/ dyed areas look colored because the pigment absorbs some wavelengths and scatters the rest. (Glossy-coated paper can add a small specular component, but ordinary paper is essentially a diffuse reflector.)