It looks like I replied to Peter Uhnák directly, so I copy my message here: If you open halo menu on topmost [in hierarchy] PanelMorph in window, you can see that layout properties have been set properly. By default hResizing and vResizing are set to #spaceFill in SpecTableLayout, so: 1. rows are the same width - therefore cellPositioning doesn't matter 2. rows are occupying the whole height - therefore listCentering doesn't matter The following layout will allow to see effects of listCentering and cellPositioning (btw cellPositioning is #center by default): layout := SpecTableLayout column cellPositioning: #center; listCentering: #bottomRight; newRow: [ :r | r vResizing: #shrinkWrap; width: 120; add: #cell11; add: #cell12 ]; newRow: [ :r | r vResizing: #shrinkWrap; add: #cell21; add: #cell22]; yourself. -- View this message in context: http://forum.world.st/SpecTableLayout-TableLayoutProperties-tp4847376p484745... Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.