Oblique Drawing

Oblique projections and drawings are used when a designer wishes to clearly depict a part's irregular face or face that contains a number of circular features. The face with the particular features is placed parallel to the picture plane with the depth lines obliquely projected from the part at either 30°, 45° or 60°. Although any angle can be used, these angles are generally recommended as they are the common angles available on commercial Set Squares. Of the three angles, 45° is the most commonly used.

Oblique drawing is believed to be the early versions of perspective drawing. They have been found on Greek vase decorations from the fourth century BC and on Chinese paintings up until the eighteenth century AD.