Polish Air Force checkerboard

The Air Force checkerboard ( _pl. szachownica lotnicza) is a national marking for the aircraft of the Polish Air Force, equivalent to roundels used in other nations' air forces. It consists of four equal squares, of which the upper right and lower left are white, and the other two – red. These are surrounded by a border of inverted colors whose thickness is one fifth the side of a single square.

Initially Polish military aircraft used different non-standarized signs in national colours (red and white), most often shields with a slanted color division line, two-color belts or red letter Z inscribed into a white square. Red and white checkerboard, with four fields, was first used as a personal insignia of a Polish fighter pilot Stefan Stec. On 1 December 1918 it was adapted as the Polish national insignia.

In 1921 there was introduced red and white border, in opposite colors, but without specified dimension. Only in 1930 relation of border to fields was specified as 1:5. According to current regulations, an additional gray border can be added (relation to the field 1:6), if the insignia is painted on white or red background.

From 1993, an order of colors was inverted (the checkerboard was rotated at 90°), according to heraldry rules, but ignoring 70-year tradition (only in 1940 in France Polish aircraft had such inverted checkerboard).