OpenType Kerkis and bold Small Caps with greek

Question

Kerkis font is an OpenType font that has Greek glyphs Small Caps both for regular and bold shapes. The names of the OTF files are KerkisSmallCaps.otf and KerkisSmallCaps-Bold.otf.

When I compile the following example, the textbf is ignored. This is not surprising, as only the regular font is declared.

If I replace KerkisSmallCaps with KerkisSmallCaps-Bold then (obviously) the bold shape is used for both lines.

\documentclass{article}

\usepackage{fontspec}

\setmainfont[
    UprightFont = Kerkis,
    ItalicFont = KerkisItalics,
    SlantedFont = KerkisItalics,
    BoldFont = Kerkisb,
    BoldItalicFont = Kerkisbi,
    BoldSlantedFont = Kerkisbi,
    SmallCapsFont = KerkisSmallCaps]
    {Kerkis}

\begin{document}
\textsc{κείμενο στα ελληνικά}

\textbf{\textsc{κείμενο στα ελληνικά}}
\end{document}

The question is, how can I make xelatex typeset the first sentence in the regular shape and the second sentence in the bold one? What options should be passed at fontspec?

Answer 1

I guess bold small caps is so uncommon that the fontspec authors didn't consider it. As a workaround you could separately define a new font command for bold small caps.

\documentclass{article}
\usepackage{fontspec}
\setmainfont[
    UprightFont = Kerkis,
    ItalicFont = KerkisItalics,
    SlantedFont = KerkisItalics,
    BoldFont = Kerkisb,
    BoldItalicFont = Kerkisbi,
    BoldSlantedFont = Kerkisbi,
    SmallCapsFont = KerkisSmallCaps]
    {Kerkis}

\newfontface\bfsc{KerkisSmallCaps-Bold}

\begin{document}
\textsc{κείμενο στα ελληνικά}

{\bfsc κείμενο στα ελληνικά}
\end{document}