Here I have a New Pair of Boys ToughSkins Relaxed Fit Double Knee Jeans Size 5 Reg.  These are new,  as you can see in my picture one of the knee padding inside is peeling off,  I only looked because it said double knee and I didn't extra padding at the knees.   I will ship them with USPS.  I measure 20x19.   I guess you can call these vintage,  I believe Sears made these years ago.