Which drawing medium will get darker over time because it tarnishes?

In what way is the story of "the qorikancha" temple evident in jaune quick-to-see smith's "trade (gifts for trading land with white people)"? symbolism in "trade" relays how native culture was co-opted by europeans elements of the creator god viracocha's narrative are reflected in the artifacts colors of gold and silver in the painting recall the interior treatment at qorikancha use of line in the painting relates to social hierarchies evident in the qorikancha floor plan

Look at las meninas by diego velasquez. this painting is a masterful example of the use of:

What is a principle of design that repeats elements to create good visual flow?