Porous glass containers and methods for making the same

A method of forming a glass container having a step porosity, the method comprising:

• providing a glass container having a glass body comprising an external surface, an internal surface opposite the external surface, a thickness T extending between the external surface and the internal surface, and an external surface layer extending from the external surface into the thickness of the glass body;
• contacting the external surface of the glass body with a first etchant and preventing contact between the internal surface of the glass body and the first etchant to produce the glass container having the step porosity, wherein the external surface layer has a porosity greater than a porosity of a remainder of the glass body extending from the external surface layer to the internal surface.