Dimension scale affects the size of the dimension geometry relative to the objects
in the drawing. Dimension scale affects sizes, such as text height and arrowhead size,
and offsets, such as the extension line origin offset.

You should set these sizes and offsets to values that represent their actual size
on paper. Dimension scale does not apply the overall scale factor to tolerances or measured lengths, coordinates, or
angles.

Setting dimension scale depends on how you lay out your drawing. There are three methods
used to create dimensions in a drawing layout:

• Dimension in model space for plotting in model space. This is the traditional method used with single-view drawings. To create dimensions
  that are scaled correctly for printing or plotting, set the DIMSCALE system variable
  to the inverse of the intended plot scale. For example, if the plot scale is 1/4,
  set DIMSCALE to 4.
• Dimension in model space for printing or plotting in paper space. This was the preferred method for complex, multiple-view drawings prior to the 2002
  products. Use this method when the dimensions in a drawing need to be referenced by
  other drawings (xrefs) or when creating isometric dimensions in 3D isometric views.
  To prevent the dimensions in one layout viewport from being displayed in other layout
  viewports, create a dimensioning layer for each layout viewport that is frozen in
  all other layout viewports. To create dimensions that are scaled automatically for
  display in a paper space layout, set the DIMSCALE system variable to 0.
• Dimension in layouts. This is the simplest dimensioning method. Dimensions are created in paper space
  by selecting model space objects or by specifying object snap locations on model space
  objects. By default, associativity between paper space dimensions and model space
  objects is maintained. No additional scaling is required for dimensions created in
  a paper space layout: DIMLFAC and DIMSCALE do not need to be changed from their default
  value of 1.0000.