You can encapsulate both leaded and fused glass panels into double glazed units.
Leaded glass panels have the outer came built in “Y” shaped came. The tail of the “Y” is held between the spacer bars at the edge of the double glazed unit. You normally need to leave 25mm space on each side. It is calculated as the reduction from the glazing size of the opening. This is required to accommodate the width of the heart of the came, the spacer bars and sealant of the double glazing assembly.
The same sizing guide is required for fused glass panels. Usually the “Y” came is designed for 3 mm glass, as it has a 5mm high heart. However, the “Y” is broad enough that the leaves can be opened to accept the thicker 6mm fused glass. It is also possible to grind a bevel on the back of the fused glass to make it easier to slip into the came.
It is best to find the person or company which will be making the double glazing unit before starting. Discussion with them at the start will enable you to determine how much allowance is needed for the spacer bars and the sealant. This will assure you in setting the dimensions for the panel you will make.