AutoCAD Line Type Scales, The Secret Truth.
The best thing about AutoCAD is that the programmers never throw anything away. The worst thing about AutoCAD is that the programmers never throw anything away!
There are now four AutoCAD variables that govern your line type scale. It can seem a little confusing, so hang on tight while we take a run through them…
LTSCALE = 1.0
CELTSCALE = 1.0
PSLTSCALE = 1
MSLTSCALE = 1
To change a variable’s value, simply type it in at the command line and enter a new value when prompted. These values are saved in the drawing, so it’s worth getting them right in your template file.
Why should I use these values?
Why have I suggested these settings? Let me run through each one in a little more detail.
This variable sets the Line Type Scale factor globally.
Use LTSCALE to change the scale factor of all linetypes for all geometry in a drawing. Changing the linetype scale factor causes a ‘REGEN’ so you can see the result of your changes straight away.
If you only draw and plot from Model space, you can use LTSCALE to scale all your line types to suit your plot scale. If you use Paper space layouts, just leave this set at 1.0.
Sets the Current Entity Line Type Scale i.e. whatever you are about to draw next!
The CELTSCALE is relative to LTSCALE. By setting CELTSCALE to 0.5 the next line you draw will have a linetype scale factor which is half that of the lines drawn previously.
You can use this feature to vary the linetype scale of your lines as you draw them. You can also change the line type scale of some geometry after you’ve drawn it by selecting the geometry and looking for ‘LTSCALE’ in the properties palette.
Don’t forget to set the ‘CELTSCALE’ back to match ‘LTSCALE’ when you’re finished.
This variable controls the linetype scaling of geometry displayed in paper space viewports – Paper Space Line Type Scale.
This variable only has two settings. Setting ‘PSLTSCALE’ to (Off) will mean that the linetype scale factor of your modelspace geometry will not be effected by the scale of your viewport.
Setting ‘PSLTSCALE’ to 1 (On) means that the line type scale of your modelspace geometry will be scaled to match the viewport scale.
If you use paper space layouts, turning paper space line type scaling on ensures that all your geometry will have the correct line type scale, no mater what the viewport scale is.
‘LTSCALE’ and ‘CELTSCALE’ Still effect the Line type scale of your geometry. You might need to use the ‘REGEN’ or ‘REGENALL’ command to see the result of any changes in your viewports.
This is a reasonably new (Since 2007), but extremely useful variable. Like Paper space line type scaling, Model Space Line Type Scaling only has two options. Setting MSLTSCALE to 0 (Off) is the default setting and will behave as Autocad always has.
Setting MSLTSCALE To 1 (On) will cause the Line type scale of any geometry in model space to be scaled by the Annotation scale. This allows you to have a preview of how the line type scale might look when seen through a scaled viewport.
MSLTSCALE Overrides LTSCALE and CELTSCALE in Modelspace, but it doesn’t effect Paperspace, so it won’t change how your geometry looks inside your viewports.
Using MSLTSCALE is a really good way of checking that your linetypes are going to look as you expect them to, without having to ‘Flick’ back and forth between Paperspace and Modelspace.
Do you know how to which Linetype definitions you should use to meet the ISO Technical drawing standard? Read these posts on defining ISO linetype definitions to find out more.