A rectangular sunglasses shape reads as streamlined and intentional without requiring you to commit to a trendy oversized situation. The proportions elongate the face and the clean lines mean the glasses work with most outfit aesthetics from casual to polished. Metal frames tend to feel more contemporary than acetate in this shape and the hardware should be minimal to maintain the streamlined effect. The lens should be generous enough for protection without being so large that the style shifts into oversized territory. Quality frame construction is particularly visible in rectangular shapes which means any flexing or wobbling becomes immediately apparent. These are the rectangular sunglasses that work because they commit to proportion rather than spectacle.