Abstract: A wall panel base trim a panel channel extending between first and second ends. The panel channel surrounds a panel groove configured for reception of a wall panel therein. The panel channel includes a blending fin extending from the channel base, the blending fin on a second side of the panel groove. A brace ridge extends between the first and second ends, the brace ridge projects laterally relative to the panel channel. A shadow flange extends away from the panel channel in a second direction, the shadow flange and the brace ridge cooperate to form a shadow line recess.