https://doi.org/10.1351/goldbook.P04682
A separation technique in which the stationary phase is present as or on a plane. The plane can be a paper, serving as such or impregnated by a substrate as the stationary bed (paper @[email protected], PC) or a layer of solid particles spread on a support e.g. a glass plate (thin layer @[email protected], TLC). Sometimes planar @[email protected] is also termed open-bed @[email protected]