The nature of production with different inks, substrates and production processes means the tonal breakdown of colours can differ greatly. A solid colour can be exactly the same but as soon as that colour is printed with screened tone and production inks, its characteristics may differ greatly from that of a software’s digital breakdown.
A Tone DB is a colour file which contains the tonal breakdowns of each 100% chip and can contain an unlimited number of colours. Tone DBs can be added to at anytime, and play a vital role in Production Colour Management, because when colours from a Tone BD are used to colour designs in AVA, tonal areas of the design will closely match the production prints.
Preparing the data
You need to create a test cylinder using the step wedge sample file supplied by AVA. (If you already have a cylinder of this type, this can be used instead.)
It should contain at least twenty steps of tone, breaking down from 100% to 0%
Once the cylinder has been made, you need to print a sample of each of your production inks and their ink mixes, under normal production conditions.
Orange 100% colour spectro read and generically broken down by AVA
Same Orange 100% colour but showing how the production breakdown of the orange colour changes hue, going more yellow.
Read the steps for each colour into a new colour file in Coloursys and name each colour. Remember to read the substrate as well. The step number will be added automatically (_0, _1, _2 etc)
Building the Tone DB
Once the data has been read into a colour file, drag the substrate colour into a colour file of its own.
Note: The creation of a Tone DB will not work if the substrate chip is in the colour file you are creating the Tone DB from).
- In ColourSys, go to Tone DB Menu > New Tone DB.
- Drag the substrate colour into the Substrate box at the top of the window.
- Enter the densities of the steps used in the Tone Steps box at the bottom of the window, for example; 0 3 5 10 15 20 etc, then go to File Menu > Save. Name the Tone DB something sensible (eg including the name of the substrate or company).
Note: You must enter the tones in the order they appear in the colour file.
- Go to Tone DB > Insert Colours from Document.
- Select the colour file that contains your measurements from the pop up bar and click OK.
- A message will show you how many colours have been replaced and how many have been added to the Tone Database.
- Select Optimise Model. The software will make some calculations and enter a dot gain curve in the graph. This decides the n value to be used. The c value is estimated by the user based on the production type it is being used for. For example, n: 10 and c: 0 are often used for transfer printing, while n: 8.5 and c: 0.5 are often used for gravure printing for wallpaper.
Note: Any colour used in a design in AVA which is not included in the database will use this dot gain curve on its breakdown. So even if a production colour has no real breakdown data, it will take the advantage of a production dot gain simulation when the database is set in the Overprint Preference.
- Go to File Menu > Save and save the Tone DB in User > Library > Application Support > AVA > Profiles > Production.
- Close the file.
- In Coloursys, go to File Menu > Open and select the ToneDB file you have just saved.
- The Tone DB will open as a colour file with the corresponding colours shown in it, including the substrate colour.
If you wish to see the tonal breakdown of the chips, select ToneDB > Chips to Tones:
To undo this action, select Tones > Chips from the ToneDB menu.