My favorite material is the aluminum prints. Not only do they look great, but they are pretty light and a great value. Paper and acrylic are both good too. I do not recommend the canvas material. It's the cheapest one and you do not see any detail in them. I have not seen what the birchwood looks like.
Update: 500px no longer offers prints.
Not yet. I used to have a client login when I was using SmugMug and Zenfolio. I've rebuilt the site by hand and will eventually build one back in.
Yes. I have a blog at sunpech.com where I blog about technology, photography, and stuff.
Maybe. It really depends.
If you want to use it as a personal wallpaper on your desktop or smartphone, that's fine.
Otherwise, if you found my photo on Flickr, Facebook, my blog, Instagram, or anywhere else, and want to republish it, it's best that you contact me before you do.
Please email me at: firstname.lastname@example.org