What should be the parameters of the PSD file when printing a banner 3 by 2 meters?

Question

Adobe Photoshop

I draw a banner design 3x2 meters, the size is indicated in cm, the resolution is 300 pixels per inch, the CMYK 8bit color mode is everything correct for a correct printout? especially interested in the question of size if I want a banner 3 by 2 meters, does it mean that I should specify the same width and length directly, or the dimensions could be completely different, i.e. For example, are they in pixels?

Answer 1

Of course, AI is better, and PS is used in cases where there is raster graphics that cannot be replaced by a vector, such as photos. Or prepare a raster in PS, and finish it in AI. In any case, save the output as TIFF without compression.
Yes, you can do whatever you like, the main thing is equivalent to 2 and 3 meters, taking into account PPI. It is more convenient to put in cm and that's it. Just check with the printer first if they need some kind of bleed or similar (eyelets for example). It may turn out that the layout should be a few centimeters larger.
The displayed PPI depends on where this banner goes and 300 can be a lot. It also affects the size of the layout. And not every car can allow comfortable work with a three-meter layout at 300ppi. So much is needed if people look at him closely, at arm's length. For example, banners that hang dozens of meters from people and without small details have a PPI of less than 50.

Answer 2

if I want a banner 3 by 2 meters, does it mean that I should specify the same width and length directly, or the dimensions could be completely different

Nobody draws billboards, and just meter banners in real size.
Read about dpi and how it works. Your layout parameters directly depend on how far from the eyes the banner will be located. In your case, well, a maximum of 96dpi