Hi, maybe you remember that I wanted this since 2017...

I finally managed to get a fuzzy background behind text:

"""
\setupbodyfont[ss,24pt]
\definecolor[tshade][t=.05,a=1,k=1]

\starttexdefinition MyCaption #1
\startMPcode{doublefun}
steps := 10 ;
rulesize := BodyFontSize/steps/3;
for step = 1 upto steps:
	draw lmt_outline [
		text = "\bf #1",
		%style = "bold", % doesn’t work
		kind = "both",
		fillcolor = "white",
		drawcolor = "tshade",
		rulethickness = (step*rulesize),
	];
endfor;
\stopMPcode
\stoptexdefinition

\starttext

\MyCaption{Eine wunderschöne Bildunterschrift}

\stoptext
"""

Remaining problems:

* lmt_outline doesn’t understand "style"; would be nice.

* I don’t understand why the white fill is not opaque.

Hraban