Hi, The dsrom math font only works partially with MKIV, and I do not understand what is happening. Consider the following example from http://wiki.contextgarden.net/Doublestroke (which I wrote, after suggestions on the mailing list). One needs the fonts, which are part of TL and are also available at http://ctan.org/tex-archive/fonts/doublestroke/ %======================================================================= \loadmapfile[dstroke.map] \starttypescript [math] [modern,computer-modern,latin-modern,ams] [size] \definebodyfont [17.3pt,14.4pt,12pt][mm] [mb=dsrom12 sa 1] \definebodyfont [11pt,10pt,9pt] [mm] [mb=dsrom10 sa 1] \definebodyfont [8pt,7pt,6pt,5pt,4pt] [mm] [mb=dsrom8 sa 1] \stoptypescript \definetypeface [modern] [mm] [math] [modern] [ams] [encoding=texnansi] \setupbodyfont[reset,modern,10pt] \definefamilysynonym [default] [doublestroke] [mb] \def\dstroke {\fam\purefamily {doublestroke}} \def\doublestroke#1{{\dstroke#1}} \starttext $\doublestroke{E} \doublestroke{1}$ \stoptext %======================================================================= This works correctly in MKII (Both E and 1 are shown in dsrom font). However, in MKIV the 1 is shown in LM Roman rather than dsrom. Is this a bug in context font handling, or a bug in the typescript? I am using: context version: 2008.12.01 10:25 This is LuaTeX, Version snapshot-0.30.3-2008112812 Aditya