wooden cage door material?

Well since I've been in the hobby, I've built quite a few different cages, always improving my design, i've never been happy with my door material. I would like to use pine because of its strength is awesome for the cost. I even did my own research on pine and concluded I should find something else to use.

Looking at other cheap woods I can get, spruce seems to be readily available. I've never used it and it looks like a pine tree to me. I cant seem to find anything about it really being bad, like having the outgassing characteristics of pine and cedar.

So would you think it to be safe? and for anyone thats used it, how would you compare its strength to pine? or does anyone have any other suggetions, i usually go to home depot or lowes for lumber

The material doesn't really matter so long as you cover and seal it properly. I used pine for the doors of my cage and plywood for the walls. Every surface received a layer of primer to seal the wood, a layer of paint to cover the primer, and a water based sealer to seal the paint. Next time I build a cage (soon hopefully) I'm going to build it out of fresh stock and seal it using a stain to give me a clean look.