Wilt wrote in post #18410856
Be aware that although a number of folks said 'Print it any size you want', that a lot of commercial printers insist that you provide them with a file which would permit 300 pixels per inch of final size...so if you wanted a 40" tall print, you would need to resize in postprocessing from starting with 1718 pixels to 40*300 size...1718 pixels is resized to 12000 pixels in the file provided to them...7X as many pixels as you started with!
I think you might struggle to print that image at 40" high mind, since at that size it would be 90.8" wide! That would be some impressive chimney breast to hand the print on too. But Wilt does have a point in that a lot of commercial labs will want you to provide them with a file that will allow production of the image at a minimum of 300 PPI, regardless of size. The other issue with large photographic prints, that doesn't seem to happen with other similar forms of art, is that instead of just standing back at the natural viewing distance, which is usually about the same distance as the diagonal size of the picture, they will try to move in close to "see the detail".
So yes you can sometimes get away with a big print at a lower effective resolution, but you really had better hang it somewhere that will make it impossible for a viewer to walk right on up to it and as I said before, view it at "nose" length.
As I said in my first post in this thread I think the image will look really nice printed at 26" wide, and actually you would probably get away with up to around 36" on the long edge. What I would do however if I were considering going that large is to the image enlargement process so that you have a file that is the required pixel dimensions at 300 PPI, and then I would crop out a couple of sections that are 1800×1200 pixels, and print them, they will be 6"×4", using a finish that will be similar to your chosen finished work, so for the acrylic I linked to I would just use glossy paper. Then just see what you think of that print at a range of viewing distances.
With that large file, if you have a monitor with an average resolution, then viewing the image at 30% or 3:1, will give a rough approximation of the size that a 300 PPI print will be. This is because the average resolution for a monitor is right around 100 PPI.