This tutorial covers the propeller blade Thickness curve. This curve defines the cross-section thickness-to-chord ratio along the blade for whatever type of section is set. For airfoils, this value is relatively straightforward since T/C is a common defining characteristic of these shapes. Other section types, such as ellipses or rectangles, have their width set by the chord (C/R) and the height set by T/C automatically. For more information about how to manipulate these curves, please refer to the Propeller Blade Control Curve Interface page.
Note that the XSec values for height and width or chord and T/C are deactivated for propeller components as these values are controlled by the Chord and Thick curves! AF_File (custom airfoil) types will have their base T/C overridden by the T/C curve. To apply a specific T/C at a given blade station, you must have a curve control point at that station and set the desired T/C.