How to set dpi in photoshop

Question

Design

Hello, dear toster(s) :)
I have a question for you; I was given an order to develop a billboard (for the first time). Since I'm a web designer, I'm used to measuring everything in pixels, but here: dpi, pixels per inch, printing, I don't even know how to set these dpi in photoshop.
Thank you very much in advance.

Answer 1

Hey hey, miracle masters ... In short (everywhere I mean the original size of the picture, if you do a strong scaling of the picture, you will get soap; to change the size of the picture without physically changing it, uncheck "resampling", then when you change the resolution it will change proportionally size in mm, this will allow you to quickly figure out what size on the print will allow you to maintain quality):
1) In standard printing (offset, digital machines) a resolution of 300 dpi is used (usually in the range of 400-225 dpi you can not bother and leave it as it is (the differences for many will be subtle), unless of course there are special requirements). Moreover, pictures like "screenshot" (with a very sharp pixel contrast) are best left as they are, without any scaling (only 100%) - pull it to 300 dpi or another resolution, there will be disgusting soap (this applies to links in InDise or Illa, for example ).
In addition, when scaling in Photoshop, I advise you to choose the correct recalculation (resampling) mode - there it is clear from the names of the menu items.
2) Regarding large print... When making large posters, be guided by approximately 500 MB of blank typhus in CMYK - this usually gives a good picture quality. If the poster is small (a la 600x900 mm), the size in bytes can become smaller (larger printers rarely use more than 200 dpi). If the poster is very large - tens of meters, then of course the file can be 1-2 Giga, even at 5-10 dpi.
3) There are no fixed figures for the resolution of pictures for printing devices. There are those close to optimal (for example, 600 dpi for a regular offset will not only make the file 4 times heavier, but will most likely give a more soapy picture after RIP). If in doubt, call the print shop, ask their designer (often this makes sense, since the technique and workflow are different everywhere).

Answer 2

Change resolution or dpi
Image-Image Size-Resolution or alt+ctrl+I
dpi = pixels/inch(pix/inch), i.e. e resolution = (so many) dots per inch

Answer 3

web 72 print 300
https://ru.wikipedia.org/wiki/Print_design
or when working with a file - menu: image->image size