Results of practice show that boron glaze is of high-performance, non-poisonous and low cost. So it is able to substitute for leadglaze.
结果证明，硼质釉料无毒、性能优良、成本低，完全可取代有毒的铅质釉。
2
Glaze is mostly translucent, but da Vinci would also slip in small amounts of pigments, such as manganese and lead oxides.
釉料大多是半透明的，但达芬奇也会添加少量色素，如锰，氧化铅。
3
In those cases where leaded frits seem necessary, it is recommended to fire to at least cone 03, to ensure sufficient reaction of lead and glaze ingredients.