Basic Question: How to make trail renderer striped instead of solid?

I am trying to make a trail renderer for a sprite which is falling. I want it to be striped and to be able to adjust the spacing of the stripes. Is this possible?

Depends which way the stripes are running. Basically you want to use a different material on the trail renderer. Your material should have a striped texture, and Unity recommends using particle shaders for trail renderer materials.