A drawing is the representation of Objects 'on a plane surface by means of lines. There are freehand drawings which are made entirely by hand and mechanical drawings, made with the aid of instruments. Vehicle drawing is a branch of mechanical drawing. The Essentials. In making a mechanical drawing the essentials are accuracy, clearness and neatness, as the Object of such a drawing is to enable one to make the part or combination pictured, without any other information than that contained on the drawing. The workman constructs as the drawing shows, not as the draftsman may have intended to Show.