Draw a vertical line

Draw a horizontal line on the new layer

The vertical line and the horizontal line are respectively "selecting range → selection of color gamut → stock by selecting"

Delete the vertical line in the selection range of the horizontal line and the horizontal line with the selection range of the vertical line.

Right-click on stock layer → selection from layer → selection area → delete

Displaying the original vertical line and horizontal line makes a check pattern.

Shape is irrelevant if vertical and horizontal lines are present