I have eventually selected all the images for next years calendar. Test prints have arrived and I have decided to go with a 28x21cm size on matte 220g/m3 paper.
Recently, I got contacted by zor.com, a Belgian print lab, that offers great prices for large prints on Alu-DiBond, Acrylic Glass and Forex. At first I was skeptical if they could provide a quality print with the low rates, they are putting out there. Hence, I moved ahead and went to get a 90x60cm image on Alu-DiBond (which they provided for free).
Read about the stories behind the pictures.