Thank you, I appreciate it.
I am actually trying to prep for print since this will be a holiday card. I tried exporting a PDF into a Photoshop and editing from there, but that didn't look great either. The results still looked pretty grainy. Shutterfly can't provide their printing specs either so I'm not sure how I need to export, but I'm hoping I'm just not making any glaring errors on my end.
Ok, I'm not entirely sure of your workflow but keep web and print heads entirely separate. If you are preparing for print, it doesn't matter a bean how it looks on the web. It has thrown away most of your info. If you're preparing for web AND print, these MUST be two different jobs, you cannot make one size to fit both.
Now, if you're preparing for print, I'm surprised you need to make PNG or JPEG. But I looked at Shutterfly; really their job is Photobooks and photo cards. You submit photos. You add text in the web design process. If you want to design your own text, they might not be the service you need. 300 ppi is great for photos, and mediocre for small text. It may be OK for the quality expected for a greetings card though, and at the size you'd normally use. Be wary of trying to squeeze in a lot of body type, could be very poor.