linewidth

Line width, or linewidth, is a measure of the thickness of a drawn line. The term is used in several fields with related but distinct meanings: in typography and vector graphics it describes the stroke width of lines or glyph outlines; in data visualization it refers to the thickness of plotted lines; in spectroscopy it denotes the width of a spectral feature; in electronics manufacturing it refers to the width of a conductive trace.

In typography and graphics, line width is typically specified in points or pixels and can be constant across a drawing or vary along a stroke (for calligraphic effects). In vector formats such as SVG and in many drawing programs, stroke-width or pen width controls rendering; anti-aliasing can affect perceived width on raster displays.

In data visualization, the linewidth parameter controls how thick the drawn line appears on screen or in print. Values are real numbers; higher values produce bolder lines and can improve readability on crowded plots, but excessive width can obscure data or overlap with markers. In some libraries, linewidth references a line's thickness in printer points or screen pixels depending on the output device.

In spectroscopy, linewidth is the width of a spectral line, often expressed as full width at half maximum (FWHM). It reflects broadening mechanisms such as natural lifetime broadening, Doppler broadening, collisions, or instrumental resolution. The linewidth determines spectral resolution and can vary with temperature, pressure, and environment; units include Hz, cm^-1, or nm depending on the spectral region.

In electronics manufacturing, linewidth refers to the width of a copper trace on a printed circuit board. It affects current-carrying capacity, resistance, and impedance. Design rules specify minimum and recommended trace widths based on manufacturing process and electrical requirements.