Trying to print 2 x 2 images from a custom layout and getting bad quality prints

[sarah3872183452po]

I am trying to print photos with a custom layout I made with photoshop. The images are 2 x 2. The photos are printing out in bad quality. What am I doing wrong? I have the PPI at 300... Thankyou 

[D Fosse]

It would help if you could define "bad" and give us a little more information -

Just to begin with, what is the pixel size of each image?