What I set out to do was take The Source (the complete font file) and The Subset and produce an inversion, whereThe Inverted Subset = The Source - The SubsetThis way if your subset is all Latin characters, the inversion will be all non-Latin characters. Save on HTTP requests and bytes (in 99% of cases) and yet, take care of all characters your font supports for that extra special 1% of cases. Unicode-optionalWakamaifondue can generate the Unicode range for the inverted subset too but it's not required (it's too long!) In other words if you have:@font-face { font-family: "Oxanium"; src: url("Oxanium-inverse-subset.woff2") format("woff2"); } @font-face { font-family: "Oxanium"; src: url("Oxanium-subset.woff2") format("woff2"); unicode-range: U+0020-007E; }... and only Latin characters on the page, then Oxanium-inverse-subset.woff2 is NOT going to be downloaded, because the second declaration overwrites the first. ... and happy type setting, subsetting, and inverse subsetting!