Problem from Carl: Posted here http://mbug.dyndns.org/example/ are two thconfig files, one with the scraps and one without and the generated PDF files. The shot B009-B010 for example looks fine in the just centerline export, but does not show up on the export from scraps (even though it has a scrap which looks correct). Analysis from Stacho: All scraps has identical coordinates of stations and in several cases neighboring scraps has identical distance between walls. Therion has one hidden feature - it tries to join scraps automatically if there is no command "join". And in some conditions the result is as in your example. Therion "thought" two neighboring scraps are of one passage. Stacho wrote me the shift of coordinates: for example 0-100, 1-101, 2-102 should help. The problem at the end is in Carl data. (comment m.s.) :) A note: Don't use visibility on/off but subtype invisible subtype bedrock You may not use smooth off when there is no one bezier curve in your data. Correct data: scrap example-11-18-th2 point 0 0 station -name B007 point 100 0 station -name B009 line wall -outline out -attr color "color col; col:=(.5,0,0);" 100 4.62962962962963 0 4.62962962962963 subtype invisible 0 -4.62962962962963 subtype bedrock 100 -4.62962962962963 endline endscrap scrap example-11-19-th2 point 1 0 station -name B009 point 101 0 station -name B010 line wall -outline out -attr color "color col; col:=(.5,0,0);" 101 4.62962962962963 1 4.62962962962963 subtype invisible 1 -4.62962962962963 subtype bedrock 101 -4.62962962962963 endline endscrap Several pictures illustrated the problem: