LO3 setting up photoshop

The measurements I will use are the same as the 'Aesthetica' magazine.

width: 21cm
Hight: 29.5cm
gutter: 

300 raze is a high quality resolution used for printing in the publishing sector. this resolution means that the final product will not look pixelated. This resolution also means the file I will be using will be lossless. The only downside is the amount of storage it takes to save them.