Measure the length and width of the wall, and determine how many vertical pieces are needed. Gather the corresponding number of 1x2 wood slats.

Choose how many diamond shapes are needed, and divide the number by the length of the vertical slats. Mark this number along the length of the boards.

Use a nail gun to position the slats vertically on the wall.

Starting with the first slat, position a slat horizontally to the adjacent slat, and miter the pieces of wood. Repeat moving up the wall until the diamond shapes are formed.

Caulk any holes that may have formed.

Paint the wall with 2-3 coats of black paint, and let it dry completely.