It’s nearly impossible to picture a world without T-shirts. For starters, Venice Beach would be unbearable, gyms would go formal, and chances are you’d be reading this in your bra. Perish the thought. Kain is here. The tightly edited new line of tees from Amanda Kain, owner of Threadbare Vintage in Topanga Canyon, consists of four perfectly updated versions of the classics: crew, V-neck, tank, and three-quarter-length sleeve. And while the slouchy pocket on all but the V give these simple tops a hint of a boyish edge, the just-right oversize cut adds the right amount of slink. In basic black, white, or heather gray, the fabric is 90 percent modal and 10 percent cashmere, which makes this everyday staple 100 percent luxurious. Imagine that. Available at Madison, 113 South Robertson Boulevard, between Alden Drive and West Third Street, Beverly Hills (310-275-1930); online at valleynyc.com. To see styles, go to kainlabel.com.