diff --git a/optex/base/math-macros.opm b/optex/base/math-macros.opm
index 8a956ee2..3f907aae 100644
--- a/optex/base/math-macros.opm
+++ b/optex/base/math-macros.opm
@@ -1059,8 +1059,8 @@
 \_def\_mathbox#1{{\_mathstyles{\_hbox{%
    \_ifnum\_stylenum<2 \_everymath{\_currstyle}%
    \_else
-      \_ifnum\_stylenum=2 \_def\_textmff{+ssty=0;}\_fi
-      \_ifnum\_stylenum=3 \_def\_textmff{+ssty=1;}\_def\_scriptmff{+ssty=1;}\_fi
+      \_ifnum\_stylenum=2 \_def\_textmff{ssty=1;}\_fi
+      \_ifnum\_stylenum=3 \_def\_textmff{ssty=2;}\_def\_scriptmff{ssty=2;}\_fi
       \_typoscale[\_dobystyle{}{}{700}{500}/]\_fi #1}}}%
 }
 \_public \mathbox ;
diff --git a/optex/base/math-unicode.opm b/optex/base/math-unicode.opm
index e9ec87f3..3161d008 100644
--- a/optex/base/math-unicode.opm
+++ b/optex/base/math-unicode.opm
@@ -85,9 +85,8 @@
     \_setunimathdimens
 }%
 \_def\_setunimathdimens{% PlainTeX sets these dimens for 10pt size only:
-  \_delimitershortfall=0.5\_fontdimen6\_textfont3
-  \_nulldelimiterspace=0.12\_fontdimen6\_textfont3
-  \_scriptspace=0.05\_fontdimen6\_textfont3
+  \_delimitershortfall=0.5\_fontdimen6\_textfont1
+  \_nulldelimiterspace=0.12\_fontdimen6\_textfont1
   \_setbox0=\_hbox{\_everymath{}$\_fam1\_displaystyle{0\_atop0}$}%
   \_Umathfractiondelsize\_displaystyle = \_dimexpr(\_ht0-\_Umathaxis\_displaystyle)*2\_relax
   \_setbox0=\_box\_voidbox
@@ -114,12 +113,9 @@
    loads the given Unicode-math fonts in three sizes given by the
    \^`\setmathsizes` macro and sets it as the math family `<number>`.
    The `<font features>` are added to the default
-   \`\_mfontfeatures` and to the size-dependent features `+ssty=0`
-   if script size is asked or `+ssty=1` if scriptscriptsize is asked.
-   If the math family 1 is loaded then the family 2 and 3 are set by the same
-   font because \TeX/ needs to read dimension information about generating
-   math formulae from these three math families. All information needed by
-   \TeX/ is collected in single Unicode-math font.\nl
+   \`\_mfontfeatures` and to the size-dependent features `ssty=1`
+   if script size is asked or `ssty=2` if scriptscriptsize is asked.
+   All information needed by \TeX/ is collected in single Unicode-math font.\nl
    The \^`\_corrmsize` `<factor><space>` can be used just before
    `\_loadumathfamily`, see section~\ref[math-preload] for more information.\nl
    The \`\_textmff`, \`\_scriptmff` and \`\_sscriptmff` are additional font
@@ -133,14 +129,14 @@
 \_def\_loadumathfamily #1 #2#3 {%
   \_edef\_optsizesave{\_the\_optsize}%
   \_optsize=\_sizemtext  \_font\_mF=\_umathname{#2}{\_textmff #3} at\_optsize
-  \_textfont#1=\_mF \_ifnum#1=1 \_textfont2=\_mF \_textfont3=\_mF \_fi
+  \_textfont#1=\_mF
   \_optsize=\_sizemscript \_font\_mF=\_umathname{#2}{\_scriptmff #3} at\_optsize
-  \_scriptfont#1=\_mF \_ifnum#1=1 \_scriptfont2=\_mF \_scriptfont3=\_mF \_fi
+  \_scriptfont#1=\_mF
   \_optsize=\_sizemsscript \_font\_mF=\_umathname{#2}{\_sscriptmff #3} at\_optsize
-  \_scriptscriptfont#1=\_mF \_ifnum#1=1 \_scriptscriptfont2=\_mF \_scriptscriptfont3=\_mF \_fi
+  \_scriptscriptfont#1=\_mF
   \_optsize=\_optsizesave \_ptmunit=\_ptunit
 }
-\_def\_textmff{} \_def\_scriptmff{+ssty=0;} \_def\_sscriptmff{+ssty=1;}
+\_def\_textmff{ssty=0;} \_def\_scriptmff{ssty=1;} \_def\_sscriptmff{ssty=2;}
 
    \_doc -----------------------------
    Unicode math font includes all typical math alphabets together, user needs not to
diff --git a/optex/doc/optex-math.tex b/optex/doc/optex-math.tex
index 57afd223..0ac20a7b 100644
--- a/optex/doc/optex-math.tex
+++ b/optex/doc/optex-math.tex
@@ -1576,8 +1576,7 @@
 \begtt \typosize[10/12]
 \addto\_normalmath {\_loadmathfamily 5 bbold }
 
-\_regtfm bbold 0 bbold5 5.5 bbold6 6.5 bbold7 7.5 bbold8 8.5 bbold9
-               9.5 bbold10 11.1 bbold12 15 bbold17 * % using all bbold*.tfm
+\_regtfm bbold 0 bbold5 6 bbold7 8.5 bbold10 * % using all bbold*.pfb
 \_normalmath  % reload the math fonts collection
 \endtt
 %
@@ -1585,8 +1584,7 @@
 `bbold*.tfm` fonts, the optical sizes are supported.
 
 \addto\_normalmath {\_loadmathfamily 5 bbold }
-\_regtfm bbold 0 bbold5 5.5 bbold6 6.5 bbold7 7.5 bbold8 8.5 bbold9
-               9.5 bbold10 11.1 bbold12 15 bbold17 * % using all bbold*.tfm
+\_regtfm bbold 0 bbold5 6 bbold7 8.5 bbold10 * % using all bbold*.pfb
 \_normalmath
 \Umathchardef \bbplus 2 5 "2B
 \Umathchardef \bble   3 5 "3C