In order to produce sharp corners in edge regions (2) of a strand (1) of deformable material which is applied to a glass pane, the strand (1) forming a spacer in the insulating glass, a tool (5) is forced against the outer corner (3) and a tool (6) against the inner corner (4). The tools (5, 6) have active portions (7, 8) which correspond to the shape of the outer corner (3) and to the shape of the inner corner (4).