Ink Limit

[Lorna Wiles]

Hi. What is the exact definition of an ink limit and what is the best way to determine what these are for each press. Will they be different for C, M, Y, and K and different again for each spot ink used? Thanks.

 

[couriergraphics]

The ink limit refers to the total amount of each color. In other words if you have a build of 30c 30m 30y 100K the ink total is 190. Different printers will require different limits. We use 360 on our heat set web press & 320 on our sheet-fed. This number will vary from shop to shop.

 

[Magnus]

Hi. What is the exact definition of an ink limit and what is the best way to determine what these are for each press. Will they be different for C, M, Y, and K and different again for each spot ink used? Thanks.

It sounds like your talking about density, rather then ink-limit?

 

[Lorna Wiles]

Thanks for the input. Magnus, it could be both. I’ll explain a little further.

We are screen printers and print rolls of fabric, miles of them every year.

Firstly I want to profile our press for CMYK work, but before doing so I would like to determine what ink limit settings I should use. Despite searching on the net I can’t seem to find any information as to exactly what an ink limit is or what tests you can use to determine what the ink limits should be set at.

Secondly if by density we mean how black a black is or how cyan a cyan is (or its croma) then any advise on this would be welcome. We don’t actually buy in a ready made CMYK ink set but mix our own from base pigments. For instance our Cyan is made up from a pigment called Blue 3G (a Phthalocyanine of some sort). How much we should add to our mix to produce an expectable cyan is a very good question. Alter the cyan and you will almost certainly have to alter M Y and K.

If ink limits and densities are related then I guess the more pigment we add the less ink we need to lay down, but of course that only works up to a point.

Any views or input would be greatly appreciated. Thanks.

 

[Stephen Marsh]

I would not expect that the tolerance is very high for putting down lots of ink?

This target may have too much ink than you are looking for, however it should give you a start (perhaps crop off the heavy inks):

Hutchcolor Images - TAC_04.tif (172 K - CMYK)


Hope this helps,

Stephen Marsh

 

[Lorna Wiles]

Thanks for the link. That’s more or less what I am looking for. So, having printed the test target what am I looking for to establish the ink limit? Also is it possible to establish individual ink limits from this?

 

[Luc St-Pierre]

In my understanding, ink limits are used to separate colors in a file with optimal quantities of CMYK values.
The maximum ink limit would be 400%. This would cause a disaster on an absorbent substrate such as newspaper or textile so it needs to be brought down. In flexo, my specialty, on napkins (tissue paper) it could be as low as 180%. I attach a test file one could print as is, and then find out what is the optimal ink limit. Wherever, on the printed results, you feel the black is black enough, add the coordinates of that point and get the correct ink limit.

 

[Luc St-Pierre]

I was'nt fast enough (lol).
BUT.... about ink limit for one ink, this does not make sense to me. Limiting inks individually throws out the whole concept of maintaining gray balance in a picture. Maybe you are thinking more of a maximum screen value? The point in the 0-100% tonal range were the print becomes solid? If so, you then need to fingerprint a tonal range and find out what is the value of the first dot printed and the point where all becomes solid.

 

[Lorna Wiles]

Thank to everyone for your replies. Much appreciated. Your help has been invaluable!