Line thickness (pen number) in Color Table
You can only set Tekla Structures pen numbers in the Color Table of Printer Catalog if you have set the advanced option XS_USE_OLD_PLOT_DIALOG to TRUE in File menu > Settings > Advanced options > Printing. If this advanced option is set to FALSE , then you are using the newer printing functionality, and the Printer Catalog is not available.
Pen numbers in the Color Table dialog box refer to the line weights used in the printed drawing. By default, pen number 0 corresponds to a line weight of 0.1 mm. The final line weight in a printed drawing is the default pen thickness multiplied by the pen number. For example, pen number 25 will give a line weight of 2.5 mm.
The line thicknesses displayed on the screen are taken from the first printer instance on the Printer instances list in the Printer Catalog. When you print a drawing, the line thickness is taken from the printer instance you use for printing.
In color drawings, the lines are shown with different thicknesses if the Use printer Linewidths check box is selected in File menu > Settings .
In black and white drawings, Tekla Structures shows the black lines on the screen using pen number thickness defined for the color in the Color Table.
You can change the default line thickness using the advanced option XS_BASE_LINE_WIDTH.