A sensitized, photo-structurable glasses and methods for producing are provided. The glasses includes Si4+, one or more crystal-agonist, one or more crystal-antagonist, and one or more pair of nucleating agents. The glasses are sensitized in that the glass reacts more sensitive to irradiation with UV-light and can be crystallized easier and with higher aspect ratios than a non-sensitized glass with equal composition. Furthermore, the sensitized glasses of this invention have smaller crystal sizes after irradiation and tempering than a non-sensitized glass with equal composition. The invention also relates to a structured glass product. Such product can be obtained by submitting the crystallized glass product to a subsequent etching step. The structured product can be used in components or as component for the application fields micro-technology, micro-reaction-technology, electronic packaging, micro-fluidics, FED spacer, bio-technology, interposer, and/or three-dimensional structured antennae.