On 2017-01-23 00:06, Alan Braslau wrote:
> On Sun, 22 Jan 2017 22:39:53 -0500 Rik Kabel  > <context@rik.users.panix.com> wrote: > >> So, how can I make the 
inner glyph (‘?’ in the example below) >> transparent, so that the 
background shows through along with >> anything else that lives on a 
lower layer? I’ve seen a method for >> constructed shapes, but nothing 
that I can apply to text glyphs. >> Undraw doesn’t do it. > > Undraw is 
simply draw using the background color. > > Transparency is a MetaFun 
extension to MetaPost (so part of > ConTeXt). > > draw q 
withtransparency (1,0.5) ; % (method,transparency) > > Alan

Hmmm. That does not work for me (with any of many method and 
transparency values).  The  ‘?’ is solid black. I do see a message in 
the log that looks related:

    mkiv lua stats  > page group warning: transparencies are used but no
    pagecolormodel is set

but adding \setcolors[state=start,cmyk=yes] does not change that; both 
the warning and the solid black glyph remain. Could this be an issue of 
the PDF viewer? Is it a font issue?

-- 
Rik