This is an image-side change, which makes a primitiveDisplayString to not fail because StrikeFontSet returns nil for (font characterToGlyphMap). Since the code, which using fast primitive looks like following: self primDisplayString: aString from: startIndex to: stopIndex map: font characterToGlyphMap xTable: font xTable kern: kernDelta I thought, why one would return nil in ( font characterToGlyphMap ). Since #xTable in StrikeFontSet implemented as following: xTable "Answer an Array of the left x-coordinate of characters in glyphs." ^ (fontArray at: 1) xTable. i think it is safe to do similar in characterToGlyphMap , this allows the primitive to work w/o failure, because otherwise, if you look at implementation of primDisplayString: aString from: startIndex to: stopIndex map: glyphMap xTable: xTable kern: kernDelta in fallback code it does same thing again (and ignoring glyphMap at all, btw). To bench a difference, leave a couple of windows with text in world and then do: [10 timesRepeat: [World fullDrawOn: World assuredCanvas] ] timeToRun before change: 645 after change: 545 P.S. since i did this in a fresh pharo-10284-dev, where changesorter is completely broken(do you aware of it?), i filed out this method as .st file. -- Best regards, Igor Stasenko AKA sig.