Costco is outstanding....beautiful color, thick layflat pages lots of editing choices. 12x12 is gorgeous.

Could be your drum need repkacement

I've used this printer for years with great results on all sizes...I do buy canon inks, but use papers from several sources.

I just bought a new Canon 5D Mark IV from Best Buy at a comparable price with Adorama and B&H and several accessories ..all legit...I was happy with the sales guy who was knowledgeable and took my list of items and filled it quickly. I also buy from B&H in NYC in the summers when I'm in the city ...you could spend hrs in that store. I tried Best Buy because it was a store I could go in person to get the products and have someone to deal with in person should problems develop.