Thanks for the help with this font stuff people! It now works. Beyond needing to change the memory settings, I was incorrectly specifying the osf font. This works though: \usetypescriptfile[type-otp.tex] \definetypeface [maintext] [rm] [serif] [minionpro,minionpro-osf][default] [encoding=texnansi] \definetypeface [maintext] [ss] [sans] [gillsans] [default] [encoding=texnansi] \setupbodyfont[maintext,rm,10pt] Now, to go back to the auto-size-switching thing, here's a variation on the suggestion by Hans: \definefontsynonym [AutoSerif] [\fontrange {MinionPro-Capt <10pt MinionPro-Regular <12pt MinionPro-Subh <15pt MinionPro-Display ??? }] (am not sure how to specify the last) So exactly where do I put this in the typescriptfile, and how do I integrate it? What I want to do is to be able to put, for example, MinionPro-BoldCapt-OSF-8y, into the "minionpro,minionpro-osf" typescript below, and each respective optical font into its respective typescript. I'm not really understanding the logic of how this would work. \starttypescript [serif] [minionpro] [name] \definefontsynonym [Serif] [MinionPro-Regular] \definefontsynonym [SerifCaps] [MinionPro-Caps] \definefontsynonym [SerifSlanted] [MinionPro-RegularItalic] \definefontsynonym [SerifItalic] [MinionPro-RegularItalic] \definefontsynonym [SerifBold] [MinionPro-Bold] \definefontsynonym [SerifBoldSlanted] [MinionPro-BoldItalic] \definefontsynonym [SerifBoldItalic] [MinionPro-BoldItalic] \stoptypescript \starttypescript [serif] [minionpro,minionpro-osf] [texnansi] \definefontsynonym[MinionPro-Bold] [MinionPro-Bold-OSF-8y] [encoding=texnansi] \definefontsynonym[MinionPro-BoldItalic] [MinionPro-BoldIt-OSF-8y][encoding=texnansi] \definefontsynonym[MinionPro-BoldSlanted] [MinionPro-BoldIt-OSF-8y][encoding=texnansi] \definefontsynonym[MinionPro-Caps] [MinionPro-Regular-OSFSC-8y] [encoding=texnansi] \definefontsynonym[MinionPro-BoldCaps] [MinionPro-Bold-OSFSC-8y] [encoding=texnansi] \definefontsynonym[MinionPro-Regular] [MinionPro-Regular-OSF-8y] [encoding=texnansi] \definefontsynonym[MinionPro-RegularItalic] [MinionPro-It-OSF-8y][encoding=texnansi] \definefontsynonym[MinionPro-RegularSlanted] [MinionPro-It-OSF-8y][encoding=texnansi] \stoptypescript Bruce