Tall Adjusted and 50% Reduction will always be grayed out in Page Setup when printing from ClarisWorks to an ImageWriter. MacWrite II and FileMaker Pro offer these options, whereas ClarisWorks does not.
In addition, ClarisWorks does not support custom paper sizes. A shareware utility called My Page Setup can modify the Page Setup dialog to enable you to create custom paper sizes within ClarisWorks. This utility has not been fully tested with ClarisWorks, but seems to work well with the Graphics and Database environments. It is unstable in the Word Processing environment.