According to the CLIM spec 29.3.1 Layout Pane Options: "If either of the :max-height or :min-height options is not supplied, it defaults to the value of the :height option." However in panes.lisp, I see: ;; NOTE: The defaulting for :min-foo and :max-foo is different from MAKE-SPACE-REQUIREMENT. ;; MAKE-SPACE-REQUIREMENT has kind of &key foo (min-foo 0) (max-foo +fill+) ;; While user space requirements has &key foo (min-foo foo) (max-foo foo). ;; I as a user would pretty much expect the same behavior, therefore I'll take the ;; following route: ;; When the :foo option is given, I'll let MAKE-SPACE-REQUIREMENT decide. May I urge you to change revert that change. The :height and :width initargs loss their usefulness this way. Also it's a bit counter-intutive. Look at (define-application-frame only-red () () (:pane (vertically () (make-pane 'application-pane :background +red+ :min-height 100) +fill+ (make-pane 'application-pane :background +blue+ :height 100)))) Wouldn't you expect to see two panes, one blue with height 100 and a red one at least 100 pixel high? The reason for this query is that I have troubles explaining the readers of my CLIM tutorial why McCLIM violates the spec and why :height as well as :width are mostly useless at the moment. See panes.lisp "merge-one-option" (Line 549) and the commented code ;; (setf user-max-foo (or user-max-foo user-foo) ;; user-min-foo (or user-min-foo user-foo)) Thanks, -- Fruhwirth Clemens - http://clemens.endorphin.org for robots: sp4mtrap@endorphin.org