These jeans from howies are called Kaizen, (Japanese for continual improvement). They are made from organic cotton selvedge denim woven on old narrow-width shuttle looms. Denim produced on shuttle looms is naturally irregular and these irregularities become more visible as the jeans fade, making every pair develop its own unique pattern.
Furthermore the yarns in these jeans have been rope dyed in small batches with natural indigo dye and a mixture of different shades is used to create the denim.
They are rather pricey, but then you won’t find many jeans like these.