Alfred's Serif Users' Forums — jpeg quality for print publishing

Re: jpeg quality for print publishing

null@example.com (Alfred) — Sat, 23 Mar 2024 10:28:50 +0000

kevinbecken wrote:

... (100%, or minimum compression) is slightly lossy, so it’s a good idea not to go any lower unless you need to....
100% agree with this.

Thanks for your endorsement, Kevin!

Re: jpeg quality for print publishing

null@example.com (kevinbecken) — Sat, 23 Mar 2024 09:27:00 +0000

... (100%, or minimum compression) is slightly lossy, so it’s a good idea not to go any lower unless you need to....

100% agree with this.

Re: jpeg quality for print publishing

null@example.com (Alfred) — Sun, 17 Mar 2024 21:11:06 +0000

ALNC wrote:

when should I choose a I.Q. lower than "best quality" and what would be the ideal quality for press printing?

Even “best quality” (100%, or minimum compression) is slightly lossy, so it’s a good idea not to go any lower unless you need to; e.g. for email, where you could find that anything above 2 MB is too big to send, or for web pages, where multiple large images will result in long page load times.

Re: jpeg quality for print publishing

null@example.com (ALNC) — Sun, 17 Mar 2024 15:18:31 +0000

Thanks Kevin. All good ideas but that "Preset" adjustment which gives me differing image quality is still a mystery to me i.e. when should I choose a I.Q. lower than "best quality" and what would be the ideal quality for press printing?

I too noticed that converting to CMYK in Affinity Photo gives a cyan colour shift, so, yes, I will post the pdf with RGB.

Re: jpeg quality for print publishing

null@example.com (Alfred) — Sun, 17 Mar 2024 14:43:02 +0000

kevinbecken wrote:

Hi, Printers recommend a resolution of 300 pixels per inch to retain the best image quality. Also remember to add bleed size to the image, usually 3mm beyond the print size, if you want your images to print to the very edge of the paper.

Document resolution is separate from the question of the best JPEG compression setting.

There’s a section of PagePlus where you can specify the amount of bleed, if any. This is generally preferable to increasing the page size to allow for bleed.

kevinbecken wrote:

If your images have multiple layers, with any transparency, then the safest option is to merge the layers to a flat image, else you can have problems.

JPEG is a flat file format that doesn’t support transparency, so any layers will automatically be combined and any transparent areas will automatically become white when you export to JPEG.

kevinbecken wrote:

Printers also say to submit CMYK, but I have always stuck to RGB and let the printer do the conversion. I've found PP will distort the RGB to CMYK conversion colours.

The experience that you describe seems to be quite common, Kevin. I suspect it would be less of a problem if printers gave proper advice about which particular CMYK profile to use, but in the absence of such information I think your recommendation of sticking to RGB is very good advice.

kevinbecken wrote:

I always output to PDF, and the printer I use can handle any version of this.

One of the ‘flavours’ of PDF/X should be suitable, but it’s always best to ask your printer what they would prefer.

Re: jpeg quality for print publishing

null@example.com (kevinbecken) — Sun, 17 Mar 2024 13:14:55 +0000

Hi, Printers recommend a resolution of 300 pixels per inch to retain the best image quality. Also remember to add bleed size to the image, usually 3mm beyond the print size, if you want your images to print to the very edge of the paper. If your images have multiple layers, with any transparency, then the safest option is to merge the layers to a flat image, else you can have problems. Printers also say to submit CMYK, but I have always stuck to RGB and let the printer do the conversion. I've found PP will distort the RGB to CMYK conversion colours. I always output to PDF, and the printer I use can handle any version of this.
You will generate some huge files, and I use WeTransfer to send to the printer if their standard upload won't support them.
Hope this helps.
Kevin

jpeg quality for print publishing

null@example.com (ALNC) — Sun, 17 Mar 2024 12:36:34 +0000

I'm wanting to produce an A4 book of high quality photographs using PagePlus x4. I'm preparing the image pages in Affinity Photo but confused as to the quality of jpeg PP requires to give good print as AP can give me a file size anywhere between 7Mb and 250Kb for the same image, dependant upon the settings within AP. Is there a recommended jpeg file size for PP? I do understand that in printing for publishing the image quality requirement is not as high as for photographic printing, but not sure how 'low' I can make the jpeg's.