This set of three menus controls various settings that affect the rest of the tools.
Line Thickness Normally the lines drawn have a width of one pixel. If you wish to change this, click and select a new thickness (up to a maximum of eight pixels). The pencil, eraser, rectangle, oval, line and polygon tools are affected by this setting.
Anti-aliasing Lines and curves normally look jagged on the screen due to the limited dimensions of pixels. Anti-aliasing allows the use of intermediate values so that objects drawn have a smoother appearance. The line, polygon and oval tools are affected by this setting.
Fill Objects drawn on the screen are normally hollow, their "insides" are transparent and show through what was previously in the drawing. Enabling this option fills the center portion with the design selected in the pattern swatch (see below). The rectangle, oval and polygon tools are affected by this setting.