We had a lengthy discussion on this topic a while ago and here is the answer I got directly from a CO:
Hello,
I'm curious about blaze orange requirements when wearing a backpack. Obviously, a backpack will cover up a significant portion of the blaze orange vest. Would you consider this as having less than the required 400 sq inches of visible material? Are there other variables to consider? I suppose a 250 lb man would have more visible blaze than someone who is 150 lb. It came up in a discussion recently and would like to have some clarification.
Thanks,
Greg
Hello,
Thank you for your inquiry. We apologize for the delay in responding to your email.
As long as you are wearing the required 400 square inches there should be no problem. You should remember however that wearing a backpack that covers a large portion of your hunter orange makes you less visible to other hunters. You may choose to purchase an orange backpack or cover your existing backpack with a piece of orange fabric or an orange vest.
We hope you have found this information helpful. If you require further assistance contact the Natural Resources Information Centre toll free at 1-800-667-1940.
Regards,
Here is the link to the discussion:
http://www.oodmag.com/community/show...and-back-packs