pub const MARK_STROKE_FRAC: f64 = 0.1;Expand description
xenopict mark layer: stroke-width: scale * 0.1, opacity 0.7.
Kept absolute (not stem-keyed): xenopict bonds and marks both used
scale * 0.1, but xpict bond ink is thinner (Liberation stem). Marks
still match xenopict’s publication ring weight.