Joe Mauer Minnesota Twins 2006 Upper Deck Sweet Spot Update Signatures. Red and blue stitching with blue autograph. Very rare. 5-10 copies were produced. If you have an Upper Deck account you may find the exact print number with the Upper Deck ID 6PXL from the back of the card. Note the card is different from other 2006 SS Signatures because instead of brown the background is all shades of gray. Please see photos. Card ships USPS Ground Advantage.