[Therion] Line label: Line printable? Are walls printable asdotted/dashed lines?

[Bruce]

- I would like sometimes to draw an Erzgang (ore load? lode? mineral 
vein?) into a mine survey. The line type Label (Beschriftung) would fit 
into that bill nicely. Is it possible to draw the line along to the label? 

You mean one line entity creating a parallel line and text? I have not seen
this, but I am sure it is possible with metapost.
Or do you mean an independent line, perhaps with arrow from text to the
subject of the label? For this see line arrow in by following the link
below.


- And it is possible to draw the line and keep the label text together 
(instead of being distributed along the whole line)? Well, or is there a 
better way?

The line label shrinks or stretches the text to fit the whole length of the
line. See the heading 'Label' in
http://therion.speleo.sk/wiki/doku.php/drawingchecklist#lines
You have some control by adjusting the scale parameter for the line label.
Personally I generally use point label, with no orientation (this way text
is always 'horizontal', even after scrap morphing distortions).  I use line
labels from time to time for special effect or emphasis.

Bruce