180 or 360 ppi?

I print my fine art prints with Image Print, an excellent RIP.  And I print on an Epson 4800.  Image Print gives you the option of printing at 180 or 360 ppi.  I’ve printed a lot of great looking, rather large photographs at 180 ppi.  A lot of my friends are shocked.  They say I’m compromising the quality of the print.  But no matter how close I scrutinize the prints I really can’t see any difference.

Enter Genuine Fractals.  Genuine Fractals really objects if you try to resize an image to 180 ppi.  The smallest it is comfortable going is 240.  To get it to accept 180 ppi I have to fake it out. 

But the fact that it defaults ot 240 raises all sorts of questions.  What if I resize at 240 ppi and print at 180 or 360?  For that matter, is there a difference between 180 and 360.  So the other day I was printing some 16X24 images and decided it was time to finally ran a test. 

I created three files at 180, 240 and 360 ppi using Genuine Fractals of course.  On the monitor there really wasn’t a lot of difference as far as sharpness goes.  (My camera for this was my trusty Canon 10D, all 6 M pixels.)  But there was a discernible difference to the colors.  The 360 had the richest colors, especially reds.  The 180 was next in richness and the 240 was the least rich.  Interesting.

So I printed them on Epson Enhanced Matte paper.  The 180 printed at 180, 240 printed at 180 and 240, and  360 were virtually indistinguishable.  But the 360 printed at 380 indeed had richer colors, especially the reds.

So what’s going on?  I don’t have a clue.  It could be one of a number of things but I suppose I would first suspect Genuine Fractals since that was the last thing that touched the file – well, nearly the last thing. The absolute last thing that touched the file was the Photokit output sharpener tuned for the ppi of the file.

So if I want richer colors I guess I print at 360 ppi.  But is the extra richness worth files twice the size of the 180’s?  I’m not sure.  You have to compare the prints side by side and look pretty closely to see the difference.  I doubt a casual observer would notice it.

On the other hand, I like to take that extra step to make my photographs the best they can possibly be so it looks like I’ll standardize on 360 from now on.

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Author: doinlight

Ralph Nordstrom is an award-winning fine art landscape photographer and educator. He lives in Southern California and leads photography workshops throughout the Western United States. View all posts by doinlight