What is Maximum Dot and Minimum Dot in Print specification?

[drummerpaco]

What is Maximum dot and Minimum dot is actually mean?
For my own interest, I would like to know what maximum and minimum dot is really mean in print world. Especially rotogravure world.

My assumtion for minimum dot is in what percentage of screen value can be achieveable when printed. For example, 3% of screen black will be engraved to rotogravure plate as small dot shape and ink can be transferred. if 2% of screen black is not printed then you minumim dot is 3%.

For Maximum dot can be where 92% black is engraved, however due to dot gain, your density is almost comes as 100% black.

Am I right on this assumtion or totally wrong track?

If you are press operator and need to find your mximum and minimum dot, how do you find the value in %?

thanks

 

[gordo]

IMHO it is best not to use dot percent as a measure of dot size. That is because the term "dot percent" is not used consistently in the industry. Often it is used (often by marketing) to refer to dot area to imply a physical dot size I.e. "We can image a 1% screen" - which actually refers to an area of tone that measures 1% but may in fact be made up of 3% sized dots. Probably better to speak in terms of microns which is a measure of physical size I.e. "This imaging system can image a 10 micron pixel" - i.e. A 1% dot at 240 lpi.

The tone values that you can represent in presswork are dependent on the type of screening that you are using as well as the dot gain compensation curves that you apply to the plate. I.e. You can print a 92% tone if you apply a compensation to your plate imaging. You can also use a hybrid AM halftone screen to restore the highlight and shadow tones that would be lost due to the resolution limitations of your imaging system.

Make sense?