What you set is ok. Usually, the size like yours can be set higher. At least 20 and at most 60 are acceptable. If you want higher precision, set it higher.

Generally, the resolution of 30 is already very good, so we can't completely look at the resolution, but also look at the print size of the picture, and the accuracy is feasible. After reading the print size in PS, it is the effect of spraying. If the printing size accuracy is poor, it is useless to have a higher resolution.