Changing Resolution in PS2024

[HFnotts]

I'm loooking for help.  I need to change the resolution and size of an image for printing in a publication.  I need to change the reolution to 300. In File size I can change these but when I either Save, Save as or Export as and then open the image again in PS and look at file size the resolution has always defaulted to 72. Why and how do I get 2024 to hold the 300 that I set?  Its only since I updated to 2024 that this issue has arisen.  Any help or advice will be much appreciated.

[D Fosse]

The image will not magically improve by changing the ppi number.

Pixels per inch, ppi, means exactly what it says.  It does not affect the image quality in itself. It's a number that defines how thinly the pixels you have will be spread out. In other words, how big it prints.

Pixels per inch. Read that again.

The bigger you print the image, the more the pixels are spread out. Spread it too thinly, and at one point, visual quality will start to suffer. That's the limit to how big you can print your file.

Traditionally, the minimum number for books and magazines is often set at 300 ppi. That defines the maximum size you can print at. So if you set 300 ppi in the Image Size dialog, and keep "resample" unchecked!, you can read out that size directly.

The question is, how many pixels do you have in your original image? Ist it enough to reproduce at the required size, with a reasonable pixel density/pixels per inch?

Export and Save For Web are intended for screen/web/mobile devices, where the ppi number is irrelevant. So it's stripped from the file altogether. An Exported file has no ppi at all, not 300, not 72, not anything.  The 72 number is assigned as a default number when the file is reopened into Photoshop, because Photoshop needs a number for other reasons. Any number will do.

[J E L]

What happens if you change the ppi to 300, then “Save as” a TIF file? When you open the TIF file again, it should retain the 300 ppi.

[HFnotts]

Yes but my publisher wanats JPEG files and when I save the Tiff to a folder to send on it has reverted to 72 which the publisher then rejects as uan incorrect resolution.

[D Fosse]

What is the pixel size width x height of one of these images, and how big do you need it to be in print?

If you have enough pixels to print at the required size, the ppi number can easily be changed without affecting the file in the slightest. Just type in 300, and you see the resulting size:

[HFnotts]

Yes, I understand that.  The issue was ion the saving element so that I could send the images to my publisher.  However, I think the matter has now ben resolved .

Very many thanks to everyone who replied.

[J E L]

Glad you got it sorted out! Thanks for coming back to let us know.