I use a 5mm brushed aluminium bed (not anodised), equipped with a silicon heater glued to the bottom. So far I print PLA using glue stick and PETG directly onto the clean aluminium bed. Below some printing temperatures that I found to work well with certain brands of filament.
- RS Pro PETG white: 235C, 95C bed, first layer speed 10%. Lower bed temperatures than 90C caused the part to come loose from the bed. The current batch of white PETG is bubbling like crazy although it was kept in the manufacturers plastic bag together with some silica gel.
- RS Pro PETG black: 235C first layer, 220C third layer, 85 bed. First layer speed 20%. Sticks almost too well to the bare aluminium