Question Verifying an assumption

[LearningTheProfession]

Common sense would dictate to me that a 600 DPI print at 12 pass would produce a higher quality print than 300 DPI print at 12 pass. Is this a correct assumption?

Thank you in advance.

(bonus question)
Is there ever a reason to not always print at the highest quality available? Seems odd that this is even an option.

 

[balstestrat]

Yes.

It takes at least twice longer to RIP at 600dpi compared to 300dpi and you can't see the difference in most use cases. Only if it's small text and stickers and such that people look closely.

When you do big jobs every day all day long you want to save that ripping time if you can. If you have jobs to fill a roll it might take 30mins or 60mins ripping.

There's sometimes a 150dpi choice as well and it's fine if it's large format graphics.

 

[netsol]

it certainly mean the file size is 4 times as large, and takes 4 times as long to print.

if it DOESN'T yield better print quality that would be between you and the manufacturer.

it practically has to be true...

 

[Notarealsignguy]

Why would you want to do that? Seems the law of diminishing returns applies with these printers.
Many may not agree with me here but in order to maximize profits, you want to find that spot where the customer is happy enough to keep coming back but not falling over impressed. If you can find that point, you can really crank out some dollars. You're not working for tips and attaboys don't pay the bills.

 

[netsol]

notarealsignguy

if i wanted to pay devils advocate, i would point out that decent pront quality is not an evil to be avoided at all costs (of course we have to avoid the "start the print job & i will come in tuesday and grommet it, if it has finished" scenario)

 

[Notarealsignguy]

notarealsignguy

if i wanted to pay devils advocate, i would point out that decent pront quality is not an evil to be avoided at all costs (of course we have to avoid the "start the print job & i will come in tuesday and grommet it, if it has finished" scenario)

I agree, and didn't mean to advocate for low quality. I more meant that these printers don't print photo quality and trying to get there is an unneeded waste of time. Its a very marginal improvement, if even that, running at super high res vs a more average setting.

 

[Jim Hancock]

Your print quality is impacted by 2 factors - image dpi and printer quality setting. For general sign work that is viewed at more than 5-10 feet away, at the same printer quality setting, you will not find any dramatic improvement above 150 dpi image resolution. If you are doing prints that will be viewed up close, then perhaps 300 dpi is a better choice. In my opinion, 600 dpi is overkill. This is of course assuming you are not magnifying the file in the RIP. The biggest impact on your output quality is the printer quality setting.

To verify this on your system, create 3 identical files at 600, 300 and 150 dpi. Print each file at different print quality settings. Mark the settings on the back of each print to eliminate the psychological effect of knowing the parameters of each print. Have someone mix them up and then look at them, grade them in order of sharpness and quality. Only then, look at the back and see the image/print settings.

You can also use these samples to help when you have a customer who is demanding the highest quality setting. As stated in above posts, higher dpi files require longer RIP processing time. Actual print times are not effected by image DPI, only printer quality settings. The determining factor should be acceptable output at the final viewing distance.

 

[chinaski]

Common sense would dictate to me that a 600 DPI print at 12 pass would produce a higher quality print than 300 DPI print at 12 pass. Is this a correct assumption?

Thank you in advance.

(bonus question)
Is there ever a reason to not always print at the highest quality available? Seems odd that this is even an option.

In theory your assumption is correct. In practice, outside of technical field, DPI is just a marketing buzzword and often a misnomer used by consumers when they really mean PPI.

If you're using too many dots per inch you might be "overcrowding" the printout, especially if your increase in DPI doesn't correspond with a decrease in printhead Picoliter size. Even at small picoliter size there is only so many droplets you can but per square inch. Imagine trying to print bright neon color and forcing your printer to print, for example 1200x1200 DPI. You're forcing your printer to lay down more droplets than desirable and your gamut will be worse for it. You can test this with making you own profile and see for yourself —I had the same intuition when I first got into the field.

With variable printheads, DPI becomes meaningless because larger droplets are better for producing saturated colors and improves contrast. If you were restricted to you ONLY small droplets printouts may look smoother but also flat.

If you need a bump in quality, try using uni-direction mode. But, of course, as others have indicated, quality improvements are marginal for the sacrifice in speed. Create you own profiles for good quality improvements without sacrificing speed.

 

[bob]

Print 150 dpi RGB images at a printer resolution of at least 4 times the image resolution. That would be 600 dpi or better. Lost of printers do 720 dpi and that's just fine with a 150 dpi image. There is never, as in ever, a need to print more resolution than that. The human eye can't distinguish a single pixel at 150 dpi.

 

[Notarealsignguy]

Print 150 dpi RGB images at a printer resolution of at least 4 times the image resolution. That would be 600 dpi or better. Lost of printers do 720 dpi and that's just fine with a 150 dpi image. There is never, as in ever, a need to print more resolution than that. The human eye can't distinguish a single pixel at 150 dpi.

Funny, this is like reading a thread on TVs. People get all caught up in quality that they can't even physically distinguish.