I normally sell my photos printed on metal, as it tends to suit my high contrast, highly-saturated landscapes, but have recently been asked about printing on canvas.
As far as I'm aware, canvas has the disadvantage of losing fine details in the print (although this is mitigated when making huge, 40"x120" prints) and having less shadow detail and more muted colours than other mediums.
I've also noticed that there are two different methods of printing on canvas - direct giclee prints (using a large-format inkjet printer) and making a normal print on photographic paper (including metallic), then bonding the print to canvas or transferring it across otherwise.
Which is the better method? What are the advantages and disadvantages of each?

