Make sure your PSE layout is viewed at 100% before you commit to printing.
Many of us create our layouts at 3600 x 3600 pixels because that translates into a high quality 12" x 12" print. Before you print your layout, ALWAYS view it at 100%. You may spot potential problems beforehand, and save yourself from printing a less than perfect layout.
When we view our entire layout no larger than what our screen size can accommodate, it can visually hide the fact that an image on our layout is of poor quality.
What's the resolution of your screen? Mine is 1600 x 1200 pixels. So, if I try to view my entire layout crammed onto my screen, obviously, not all 3600 x 3600 pixels can be displayed. To see it all, go to 100% view and scroll left/right and up/down. If everything looks good, you will likely be pleased with the print. If you see unwanted blurry, blotchy areas, you'll have to decide if you can live with that, or take action to make improvements.
(I wrote this post because I'm helping someone understand the importance of viewing at 100%, pictures that have been resized.)