Flat glass and method for producing flat glass

The invention relates to a method for selecting a sealing material for recesses, depressions or the like in a sealing device for producing flat glass having a high processing temperature VA, comprising the following steps:-providing at least one sealing material,-providing at least one sample body for each sealing material, -measuring a first length of the respective sample body in at least one spatial direction,-heating the respective sample body over a predetermined time to a predetermined temperature,-measuring a second length of the respective sample body in the at least one spatial direction,-ascertaining a length difference between the first and second lengths of the respective sample body,-determining the length difference between the first and second lengths of the respective sample body, -checking the respective length difference of the sample body if the relative length difference is less than 1% at a predetermined temperature of 1400 DEG C and/or o is less than 2% at a predetermined temperature of