Like triple blown this is a very loose term. In reality, it takes about 2-6 times to meltdown and blow out a piece of glass. The thicker the inside glass, the more it needs to condense and expand to get the glass all even. To know if a piece is good, look inside. If it is smooth, the blower melted the color in properly. If there are bumps, the blower needs to put in more work.