Sets the current lineweight, sets the lineweight units, controls the display and display scale of lineweights, and sets the DEFAULT lineweight value for layers.
Button
Ribbon: Home
tab 
Properties
panel Lineweight Menu:
Format LineweightAt the Command prompt,
enter lweight. 
Command entry: lweight (or 'lweight for
transparent use)
The following options are displayed.
Displays the available lineweight values. Lineweight values consist of standard settings including BYLAYER, BYBLOCK, and DEFAULT. The DEFAULT value is set by the LWDEFAULT system variable, which has an initial value of 0.01 inches or 0.25 mm. All new layers use the default setting. The lineweight value of 0 plots at the thinnest lineweight available on the specified plotting device and is displayed at one pixel wide in model space.
Displays the current lineweight. To set the current lineweight, select a lineweight from the lineweight list and choose OK.
Specifies whether lineweights are displayed in millimeters or inches. You can also set Units for Listing by using the LWUNITS system variable.
Controls whether lineweights are displayed in the current drawing. If this option is selected, lineweights are displayed in model space and paper space. You can also set Display Lineweight by using the LWDISPLAY system variable. Regeneration time increases with lineweights that are represented by more than one pixel. Clear Display Lineweight if performance slows down when working with lineweights turned on in a drawing. This option does not affect how objects are plotted.
Controls the DEFAULT lineweight for layers. The initial DEFAULT lineweight is 0.01 inches or 0.25 mm. (LWDEFAULT system variable)
Controls the display scale of lineweights on the Model tab. On the Model tab, lineweights are displayed in pixels. Lineweights are displayed using a pixel width in proportion to the real-world unit value at which they plot. If you are using a high-resolution monitor, you can adjust the lineweight display scale to better display different lineweight widths. The Lineweight list reflects the current display scale.
Objects with lineweights that are displayed with a width of more than one pixel may increase regeneration time. If you want to optimize performance when working in the Model tab, set the lineweight display scale to the minimum value or turn off lineweight display altogether.
