Vintage buying WWII Color Cartoon Art Mailing Envelopes Militaria Unused RARE 1940s

These are amazing! Never seen these before in all my years of collecting.
Bright colors with no buying fading, been in a shoe box in the closet for decades.
They have minor wrinkles and scuffs for age and storage, see pics.
No writing on them, see pics.
No rips, tears or holes, see pics.
Gummed edges still have residual, see pics.
Research shows no artist or business, has copyright on lower left of each envelope, see pic.
Standard business size envelopes measure approx 9 1/2" x 4".
My Mom and her Brothers went thru this era, I admire them greatly for it.