Observations on Jeans

Was just ironing my Coldwater Creek Jeans and made some interesting observations...
On this pair - waistband cut on straight of grain at center back - where there is a seam in the waistband underneath the belt loop....and then the waistband is bias at the center front...
Whereas...on this lighter pair - it is opposite - straight grain at front, and bias at back...????
And - the back of the legs are MUCH larger - all the way down - than the fronts...back of the jeans is at the top of the photo...and note that the INSEAM is topstitched - NOT the side seam. Furthermore, the topstitching - on this seam only, has only one row of gold stitching, the other is navy and you can't see it... ???

ANd - the side seams are NOT topstitched - which drives me CRAZY by the way - cause that seam allowance always flips the other way - and ironing my jeans is one thing - but inside out first to press the seam allowances properly - that's another issue - I will NOT do!
If anyone has explanations for all these observations - reasons why - etc. please enlighten me and the rest of us.

I wonder............does anyone else notice things like this while ironing?

By the way - if you make your own jeans, or need to do hemming or altering - I carry that gold (Topaz) Jeans Stitch thread - it is heavier than normal...
And I'd recommend a Jeans/Denim Needle size 90 or 100 - test to see which works for you...
Or even perhaps the Topstitching Needle...size 90 or 100...
Wish I could say exactly which one would work, but all depends on your machine, and the denim weight.
Needles are 25% off regular prices EVERY DAY at www.londas-sewing.com

Was fun to teach my Care & Feeding of your Sewing Machine class at the Cincinnati Creative Festival - and it was VERY well received. Look for it at more sewing shows around the country. Think I'll even revive my old class taught at my fabric store years ago: Londa's Secrets....

For a written version of most of the Care & Feeding class - find it at my Free Info, along with lots of other great FREE information!
ish I could