For exterior use it is always recommended to add zinc oxide. This offers greater resistance to dirt, pollen, algae and mould as well as speeding up the drying process.
This product is only to be used as an additive to the Allback linseed oil paint.
Add 10 to 20% to the Allback linseed oil paint. (10 to 15% for darker colours and up to 20% for lighter colours. Blue colours add only 5 to 10%) and mix well.