The following text has protrusion and is justified.

\setuplayout [width=6cm]
\definefontfeature [default] [default] [protrusion=pure]
\setupalign [hanging]
\showframe
\starttext
  \spaceskip=1ex plus 1ex minus .2ex
  \input knuth
\stoptext

> forcing a constant distance.

If you provide stretch and shrink the distance is not constant.

Thank you! I dont understand this command, what does "1ex plus 1ex minus .2ex " excactly mean? Does it mean the consecutive distance is element of the interval [0,8ex;2ex] or what?

> The question is, only to add an minimal distance, wich has not to be
> undercut while protrusing and justifying.

Example please

Marco

I am asking for the example :) Or what do you mean. Your example above is exactly, what I was
searching for. Only the syntax have to be understood.

Huseyin