I think Franchini made his murrine by lamp working in order to produce polychrome canes which he subsequently used to produce more complex canes. The difference is that he hot worked all stages. I am relying for my information on the Sarpellon book mentioned in a previous post in this thread. It quite possible that I have misunderstood.

Sarpellon distinguishes the techniques used by Franchini and his precursor, the reinventer of the millefiori technique, Bussolin who produced his canes at the glassmaker's furnace. The technique used by Dei Rossi is different again and is more like making a cold mosaic of glass canes to make the complete image.The canes are not fused until they are taken to the furnace.