I was wondering if there are any kind of spaces which (partly) fix the spacing between characters. For example, typesetting "Chapter 1", I would like to keep the space from stretching at the same rate as the surrounding spaces (just like ck ligatures in old German texts would be prevented from stretching, or the space in do n't (sic) in early 20th century American texts). I currently use "\ " to prevent a line break "~" to prevent extra space after a period \, \; etc. as fractions(?) of the normal space (i.e. they change at the same rate as the normal space when stretched) Are there any other types of spaces I should be aware of? I would be most grateful for any comments, especially concerning the existence of a slow-stretching (or non-stretching) space... Thank you, Severin