How to correctly apply paste gold, paste platinum an paste lustres on screening.
These golds may be used just as they come out of the packing or diluted between 5 and 10% aprox. Sometimes this dilution is necessary to give the gold a better fluidity if there has been a loss of solvent by evaporation, because of a too long storage time or a long use on the screen.
We recommend the paste gold that stays a long time on the screen to be renewed from time to time with new paste gold or adding small quantities of solvent. If this is not done the viscosity increase of the gold on the screen may originate application problems, adherence to the spatula or sticking of the screen on the item to be decorated. If this is tamponage of the pores is noticed during a short time without using the spatula, it can be removed by passing a damp cloth on the printing side in order to make the sticked gold more fluid. it’s important that the decorated items dry in an atmosphere free of dust and humidity in order to avoid that undesired particles deposit on the same.
The firing for paste golds takes place in the same conditions than for the liquid golds at the following temperature scale:
Porcelain 740 – 840ºC
Glass 540 – 580ºC
For the largest application area of gold paste in the field of direct screening temperatures are between 800 and 840ºC, in tunnel kilns with 45′ cycles from cold to cold.