AutoCAD - Adding Bespoke Linetypes to drawings

By Dennis Collin

I was recently asked a question about how to create bespoke linetypes, in addition to the out of the box examples that ship with AutoCAD as standard.

This is a relatively easy thing to do once the linetype definition file, acadiso.lin, is located within the support folder.

In a previous blog I mentioned how the file can be located from the AutoCAD command line.

https://www.cadlinecommunity.co.uk/hc/en-us/articles/360001501158-AutoCAD-2020-How-to-locate-critical-support-file-locations

The acadiso.lin file is just a simple text file which holds line pattern definitions. Opening this file in Notepad and scrolling to the bottom enables users to place their own information for bespoke patterns. In this example I will create a building line style that would be useful for small scale site survey plans.

The graphic will be a rotated letter ‘I’ which will be arrayed along a drawn length of line. The character in the Arial font is very simple and will give a simple hatch effect.

Adding in the following lines of text in the definition file will set the style

*BUILDINGLINE,BUILDINGLINE _/_/_/_/_/_/_/_/_/_/_/_/

A,4,-0.0,["|",STANDARD,S=4,R=45,X=1.0,Y=1.2],-0.0000005

The first line sets the style name and provides a rough preview of the custom line pattern.

The second line sets an Alignment parameter with a positional offset, in this case a 4 unit repeat using the “I” character from the Standard text style, a scaling option of 4, a rotation angle of 45 and a correctional offset to ensure the rotated character stays on the right side of the line without over spilling.

Once saved the linetypes can be loaded into individual drawings or template files ready for users to work with.

A similar process can be used to produce a fence line, an oblique symbol breaking a line.

*UKFenceLine,Standard Fence ---- / ---- / ---- / ---- / ----

A,12.5,-5,["/",STANDARD,S=4,U=0.0,X=-3,Y=-1.5],-5

Remember to put any bespoke linetypes at the end of the file for easy reference. If two definitions have the same name, the one that appears last in the file will take precedence.

Feel free to experiment, also remember to back up any custom files in the event of typos or invalid values!