enclosure glove box 30 such as that shown in fig1 enclosure 30 should be connected to a pressure control system not shown capable of providing the enclosure with an atmosphere comprised of substantially inert gases and at a pressure greater than the pressure of the ambient atmospheric pressure outside the enclosure suitable pressure control systems for maintaining a pre determined pressure within an enclosure are well understood and no further description should be necessary in an example of the above described process two frit sealed glass sample envelopes were manufactured in accordance with an embodiment of the present invention for the first envelope sample a a first sio 2 based glass substrate having dimensions of 50 8 mm u00d7 50 8 mm was hermetically sealed with a frit to a second sio 2 based glass substrate having the same dimensions both substrates were approximately 0 7 mm in thickness the glass envelope did not contain an oled element within its interior to form the envelope a frit wall was formed by dispensing a glass frit paste onto the second substrate in a closed circuit or frame pattern having dimensions of 40 mm u00d7 40 mm the second substrate comprising the frit frame was then heated in an oven to pre sinter the frit wall the frit wall had a height of about 14 u03bcm within u00b1 1 u03bcm the first substrate was placed on a steel plate in a glove box comprising a substantially nitrogen atmosphere subsequent to the pre sintering the second substrate was placed on the first substrate.