Abstract: A thermally insulating glass panel comprises two spaced apart sheets of glass enclosing a low pressure space and interconnected by a peripheral joint of fused solder glass and an array of support pillars, and a pump-out tube used to provide communication between the low pressure space and the exterior of the panel during the creation of the low pressure space. The support pillars each comprise a preformed core of a selected geometry and a selected material and a coating of solder glass at least in the areas between the preformed core and the sheet glass. Preferably the preformed core is spherically shaped and completely coated by solder glass. The preformed core serves to separate the glass sheets during the heating process of the panel's fabrication when the solder glass is in its molten state, and the solder glass serves as a mechanical joint to support the glass sheets after solidification.