If you are using the water based Auro 'Aqua' range of paints, such as (250, 251, 253, 260, 261, 267), then we would suggest using Auro 117 primer. This primer is perfect when you're painting onto woods rich in tannin or active substances (this is mostly in hard woods and other exotic woods) - this great Auro primer improves both the drying times and helps stop discolouring substances bleeding through the paint.
If you are using the water based Auro 'Aqua' range of paints on woods not requiring AURO 117 we would recommend using Auro 127 primer (as this product as replaced the older recipe Auro 124 Wood primer)
If you need to prime wood, cork, clay & absorbant surfaces such as these, especially before you apply waxes and oils, then Auro 121 primer is the perfect choice. This primer can also be used by itself, even as a finish and can be coloured. Multi purpose!
If you need to prime metal, such as untreated steel or even iron, both interior and exterior we would suggest using Auro 234 metal primer as the primer of choice