A supply of single-ply, fan-folded sheet stock material (100) includes a holder that has inclined support surfaces (114, 116, 120, 122) and intersecting support walls (124, 126) that support the support surfaces in their inclined orientations. The holder has a W-shape cross-section, with inclined outer support surfaces (114, 116) and inclined inner support surfaces (120, 122) that may meet in the middle. The inner support surfaces generally are perpendicular to adjacent outer support surfaces to support a generally rectangular stack (102) and sub-stacks (110, 112) of single-ply, fan-folded sheet stock material. A method includes laying open a stack of single-ply fan-folded sheet stock material to form two sub-stacks of sheet stock material and operating a dunnage conversion machine to simultaneously draw sheet stock material from both sub-stacks of sheet stock material, thereby providing a two-ply sheet stock material for conversion into a dunnage product.