Resolution and Color
(1) When creating materials for print within Photoshop, it must first be created at 300 pixels per inch and in CMYK color mode to get the best print quality from your Photoshop file. Any file created with less than 300 pixels per inch will print blurry or pixelated. Changing the resolution of a file that has already been created with less than 300 pixels per inch will not help the quality.
Saving your file as a Hi-Res PDF
(2) Go to File pull down menu and select “Save As…”
(3) With the Save As window open, name and select a location for your PDF such as your desktop. Next choose “Photoshop PDF” next to Format. Uncheck “Layers” then click “Save”. You’re done!