Egg packers are counting down to early 1997, when the industry is expected to move en bloc to the new grade names and weights. From the beginning of this month the new weight bands for egg sizes may be used: 73g+; 63-73g; 53-63g; 43-53g and under 43g. These weights, along with the very large, large, medium and small grade names, will be mandatory at the end of next year - as will single grade boxes. The intervening 18 months will be trying for packers still using mechanical graders, since there are few engineers available to recalibrate lines for the 2g drop from current weights. The flat-footed but accurate 'very large' grade is here to stay.