Where Are My Linetypes?

As the “CAD Guru” for one of Melbourne’s larger architectural practices, I’m often called on to solve problems that users face. I’ve found that the same questions tend to surface with rather monotonous regularity, so I’ll include a few of them on this blog. I thought that readers may (possibly) benefit from them. The first one is a relatively long one, so please bear with me. If you have any comments or suggestions, don’t hesitate to email me at trousers.pgodfrey@netspace.net.au (remove trousers to reply!) For this tip at least, I’m most interested if you can come up with any other ways to fix linetypes.

Where Are My Linetypes?

Often, people have trouble getting linetypes to display correctly. Typically, a line which should show as dashed looks like a continuous line. Some of the most common reasons for this are:

1. The drawing’s LTSCALE is not correctly set. For a 1:1 drawing (like a plot sheet in paper space) this should be set to 1.0. For other scales, use the plot scale as the LTSCALE. For example, a 1:100 drawing in model space might have LTSCALE = 100. Note that your office may vary if you use a different linetype definition.

To change the drawing’s LTSCALE, type .LTSCALE at the command prompt. Note the “.” before the LTSCALE. This ensures that the built-in LTSCALE command is used rather than one which may have been undefined or altered by, say, a lisp routine.

2. Layer definition. An obvious one, perhaps, but still worth checking. The layer the entity is on should be defined with the desired linetype.

3. Object linetype should be “bylayer.” Sometimes objects can be defined with linetype “continuous.” This will prevent the object taking on any other linetype such as dashed. Find this in the MODIFY dialog box, accessed by typing MO at the command line. It’s in the General section of the dialog box.

4. If this looks OK, then check the LT scale of the actual object. The object LT scale acts as a multiplier of the global LT scale referred to above. This should be 1.0, but sometimes people change this to another value. Again, find this in the MODIFY dialog box, accessed by typing MO at the command line. It’s in the General section of the dialog box.

5. If you’re having trouble with linetypes in paper space, switch to model space and see how they look. If the linetypes show correctly in model space, but not paper space, check the PSLTSCALE setting. It should be set to 1, not 0.

6. Linetype definition. If all this fails to solve the problem, you might have an incorrect linetype definition loaded into the drawing. Use the LINETYPE command to reload the chosen linetype. Check with your CAD Manager to check which linetype definition file you should use. In our office, the linetype file to load is called ACAD.LIN, not ACADISO.LIN. It might even pay to check that the ACAD.LIN file hasn’t been altered: open it in Windows Notepad and check the definitions in it.


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