Subtractive

Subtractive refers to processes or systems in which material or light is removed or absorbed to produce the final result. In color theory and printing, subtractive methods rely on pigments or dyes that absorb certain wavelengths of light, shaping the color that is reflected or transmitted. In manufacturing, subtractive processes remove material from a workpiece to achieve the desired shape or tolerance.

In color theory, subtractive color mixing uses pigments such as cyan, magenta, and yellow. Each pigment absorbs (subtracts) certain wavelengths and reflects others. When combined, these pigments absorb more wavelengths, producing darker colors. In printing and imaging, the CMYK color space extends subtractive mixing by adding black (K) to improve depth and reduce ink usage. White is the color of the substrate and the absence of ink, while black is achieved by combining pigments and the neutralization of light.

In manufacturing, subtractive processes remove material to create parts. Common subtractive methods include milling, turning, drilling, and laser or waterjet cutting. Techniques are widely used in metalworking, woodworking, and plastics. Subtractive manufacturing often yields high-precision surfaces and is well-suited for complex, rigid parts, but can generate waste material and require tooling changes for different geometries.

In music technology, subtractive synthesis builds sound by starting with a rich waveform and using filters and envelope shaping to subtract harmonics over time. This approach contrasts with additive synthesis, which constructs sound by combining many simple tones. Subtractive synthesis has been prominent in analog and digital synthesizers, shaping timbre through frequency filtering and dynamic control.

Subtractive concepts also appear in other fields, where elements are removed or filtered to achieve the desired outcome, from data processing to printing, and beyond.