Hi all Just when I thought I was getting comfortable with hierarchies of maps with various combinations of previews and offsets. I can no longer put off the realisation that I don't understand how to display a preview if Therion decides it will not do it with the default behaviour. I suspect the solution lies with the revise command; but how to make it work? The following text from the therion book makes reasonable sense, and generally works just fine. "_ preview <above/below> <other map id> will put the outline of the other map in the specified preview position relative to the current map. Preview is displayed only if the map is in the map-level level as specified by the select command. Use the revise command if you want to add maps from higher levels to the preview." However the following does not seem to give enough information to proceed. "`revise' Description: This command is used to set or change properties of an already existing object. Syntax: The syntax of this command for object created with \single line" command is revise id [-option1 value1 -option2 value2 ...] For objects created with \multi line" commands is syntax following revise id [-option1 value1 -option2 value2 ...] ... optionX valueX data ... endrevise Context: all Arguments: The id stands for object identifier (the id of an object you want to revise must always be specified)." Tips on how to refer to a previously defined map (easy?) and which options need to be changed to which values(not so easy?)? A small example anyone? Thanks Bruce