モリサワ TypeSquare が @font-face ルールを作成するときに、ウェイト情報が含まれないので、そこをいいがにする (Firefox のみ有効)

typesquarefix.js

(function() {
    var fl = document.styleSheets.length
	, timer = setInterval(watch, 100)
	;
	
	function watch() {
		if (fl === document.styleSheets.length) return;
		clearInterval(timer);
		iiganisuru();
	}

	function iiganisuru() {
		var ss = document.styleSheets[document.styleSheets.length - 1]
		, rules = ss.cssRules
		, rewrited = []
		;
		for (var i = rules.length - 1; i >= 0; i--) {
			var rule = rules[i];
			if (rule.cssText.indexOf("@font-face") >= 0 &&
				/\b(?:Bold|ExtraBold|Heavy|ExtraHeavy|Ultra|MB1|MB31)\b/.test(rule.cssText)) {
				rewrited.push(rule.cssText.replace(/font-family/, "font-weight: bold; font-style: normal; font-family"));
				ss.deleteRule(i);
			}
		}
		for (i = rewrited.length - 1; i >= 0; i--) {
			ss.insertRule(rewrited[i], rules.length);
		}
	}
})();