Methods and apparatus for forming high aspect ratio metallic glass, including metallic glass sheet and tube, by a melt deposition process are provided. In some methods and apparatus a molten alloy is deposited inside a tubular channel formed by two concentrically arranged substrates, and shaped and quenched by conduction to the substrates in a manner that enables the molten alloy to vitrify prior to undergoing substantial shear flow. The deposition method allows the molten alloy to be deposited and formed while being quenched, without undergoing substantial shear flow.