We claim the ornamental design for a buffing pad backing plate, as shown and described.
FIG. 1 is a top perspective view showing a back face contour of the buffing pad backing plate attached to a buffing pad.
FIG. 2 is a top view showing the back face of the buffing pad backing plate attached to a buffing pad.
FIG. 3 is a sectional view taken on line 3—3 in FIG. 3 showing a contour of the back face of the buffing pad backing plate.
FIG. 4 is a enlarged detailed sectional view taken from the top portion of FIG. 3 showing a more detailed view of the contour of the back face of the buffing pad backing plate attached to a buffing pad.
FIG. 5 is a side view showing the buffing pad backing plate attached to a buffing pad; and,
FIG. 6 is a bottom view showing a front face of the buffing pad attached to a buffing pad backing plate.
The broken lines represent portions of the design that form no part of the claim.