 For a period in the 1960s, numerous models emerged in which the brows were constructed from aluminium; following the style's resurgence in the 2000s, browlines made wholly out of one type of metal with less pronounced brow portions became popular.Monobrowlines are a variant of browlines in which the bridge is contiguous with the caps, creating a solid, unbroken line across the top of the frame.The style dates back to the Shuron Stag, a browline prototype, which enjoyed some brief popularity before being replaced by the Ronsir as Shuron's flagship frame.