Andrew
I cannot get preview/offsets to work for projected elevations, should they, the thbooks seems to say any map!!
See this earlier discussion thread http://article.gmane.org/gmane.comp.gis.therion/4203/match=level+preview+off set Elevation offsets should work fine, as the link above suggests and elevation previews have been problematic - I think I have had them working, but cannot remember for sure, sorry, too many tasks stacked up to want to go looking for examples at present. As for using revise to add maps of higher level. Since 2008 I have been searching for enlightenment! This search might be helpful in starting out on your quest... http://search.gmane.org/?query=revise+level+preview&author=&group=gmane.comp .gis.therion&sort=date&DEFAULTOP=and&xP=Zrevis%09Zpreview&xFILTERS=Gcomp.gis .therion---A May the force be with you Bruce