New sheetfed

[ar17]

Dear all,
we just finished acquiring two brand new machine, a heidelberg press and a komori... both brand new... after press calibration, the recorded dot gain value is quite far from my established dot gain curve. the heidelberg press needs 5% in the 80 screens and linear all the way down. the komori needs 7% in the 20 screens and linear going up. is this natural for new machine? my establish dot gain for my older presses is 4% in the 80 screens, 7% in the 50 screens and 5% in the 20 screens; forming a parabola which is not forming in my two new presses. please give input if this is really natural, for new machine to have no dot gain but rather needing further additional dots to match ISO 12647-2 dot gain value.

thanks...


Ariel

 

[loopyg66]

It's called a 'mystery of lithography'. You could line up 3 brand new komoris or whatever and they will not all print the same. That's what the ISO 12647-2, and G7 is all about, coming up with plate curves for each press to make them all print to the standard.

So, no, this is not unusual..............