Preparing Files For Print and Printing Services

[Brendan Dozier]

I'm new to having images printed for display, looking for advice on preparing files and what to look for (and watch out for) in a professional printing service.
Currently I'm wanting to get some prints (not canvas) in the 8 x 10 size range. Any advice is appreciated, here's a few questions I've had:

It seems most services require a tiff file at 300dpi, but some print from jpeg files - what is the difference? Can you really get a good print from a jpeg?

I have a few tiff files that I processed in photoshop at 240 dpi to start. Will changing the image setting from 240 dpi to 300 dpi mess up that image or prior processing?

I realize that more sharpening is required for larger size files, and know to watch for halos, but is there anything else you should be looking for in the pixels, when sharpening for high quality printing output?

I'm guessing, unless you have prior experience with a printing service, you really need a proof print to work from to accurately assess the image quality, color, and proper amount of sharpening.


Thanks for your help in advance,

- Brendan

[Roger Clark]

I'm new to having images printed for display, looking for advice on preparing files and what to look for (and watch out for) in a professional printing service.
Currently I'm wanting to get some prints (not canvas) in the 8 x 10 size range. Any advice is appreciated, here's a few questions I've had:

It seems most services require a tiff file at 300dpi, but some print from jpeg files - what is the difference? Can you really get a good print from a jpeg?


Hi Brendan,

Yes, you can make a great print from a jpeg, as long as it is high quality.



I have a few tiff files that I processed in photoshop at 240 dpi to start. Will changing the image setting from 240 dpi to 300 dpi mess up that image or prior processing?

If you do an interpolation step, you'll need to do new sharpening. If it is a simple change of the ppi with no interpolation, then there is no change in quality.



I realize that more sharpening is required for larger size files, and know to watch for halos, but is there anything else you should be looking for in the pixels, when sharpening for high quality printing output?

It depends on the printer. You'll need to try some different levels to see which you like.



I'm guessing, unless you have prior experience with a printing service, you really need a proof print to work from to accurately assess the image quality, color, and proper amount of sharpening.


Yes, that is a good idea.

The other thing is check the histogram. If the histogram peaks below mid-level on the horizontal scale, the print will likely appear dark. I try and make the histogram at mid or higher level.

Know the printer and it's colors, even with a profile and soft proofing. For example, many printers have trouble with green, and if so, boost green saturation.

Good luck,
Roger

[Brendan Dozier]

Thanks very much, Roger, appreciate your expertise. If you don't mind, just to clarify:

What is an "interpolation step"?

What is considered a high-quality JPEG? File size? Resolution?

What JPEG file size and resolution settings would be adequate for making a high-quality 8 x 10 inch print?

[Roger Clark]

Thanks very much, Roger, appreciate your expertise. If you don't mind, just to clarify:

What is an "interpolation step"?

Hi Brendan,
If you change the number of pixels in the image. For example in photoshop under image -> image size, the resample image box is checked.



What is considered a high-quality JPEG? File size? Resolution?

Depends on the image, but generally 11 or 12 out of 12 (in photoshop) or 9 or 10 out of 10 in other image processing programs.



What JPEG file size and resolution settings would be adequate for making a high-quality 8 x 10 inch print?

Set your target ppi, then save the jpeg at maximum quality.

Roger

[Brendan Dozier]

Thanks Roger,

and finally:S3:, at max quality and 300 ppi, can you tell a difference between a Tiff and Jpeg print? If so, does the Tiff normally look better?

[Roger Clark]

Thanks Roger,

and finally:S3:, at max quality and 300 ppi, can you tell a difference between a Tiff and Jpeg print? If so, does the Tiff normally look better?

Hi Brendan,
I can not tell the difference between an 8-bit tiff and a highest quality jpeg, either printed or on my calibrated monitor, but then my area are not that great. I've subtracted two such images and it is almost a perfect match, so I would bet no one in a true blind test could tell the difference, unless it was a special selected image. Years ago when I had my 4x5 images drum scanned, the files were too big to put on a CD (this was before DVD) and I had no way to get a gigabyte tif file to my pro print lab, so they suggested I just put the image as a jpeg on a CD. The prints were great.

A 16-bit tif can contain more detail that when stretched would show more than a jpeg, but that is a different story.

Roger

[Brendan Dozier]

Thanks Roger

I just had some sample jpegs printed, and they look pretty good. They gave me a lower price because the file was already adjusted and sharpened, was able to review the proofs and make some last minute adjustments right there at the lab.