I have a basic print profile for a Brother label printer (I realise it's not what Publisher is for, but it's convenient while I'm sorting something else out more permanent!). Though I try to save the paper size as 62 x 100 mm, when I load the profile both values are set to zero. In addition, after loading the profile, those values cannot be edited until the paper size is changed to another option, then set back to custom.
Print profile attached.
address-label.profile