Conditions that must hold when you measure cyan, magenta, and black variation
Both readings need the same instrument, the same spot, and the same backing. Change the backing and 4 means nothing. For this variation, follow the job ticket. Don't rely on what this shift remembers.
Both readings need the same instrument, the same spot, and the same backing. Change the backing and 4 means nothing. For this variation, follow the job ticket. Don't rely on what this shift remembers.
Which conditions have to hold together
Don't use the proof deviation of 5 to pass within-batch variation, and don't put yellow's 5 onto cyan, magenta, and black. If the conditions differ, the two numbers cannot sit together for a comparison.
Conditions side by side
| Item | Do this | Don't |
|---|---|---|
| Cyan, magenta, and black variation | Both readings need the same instrument, the same spot, and the same backing. Change the backing and 4 means nothing. For this variation, follow the job ticket. Don't rely on what this shift remembers. | Write only a feeling |
| A common miss | Don't use the proof deviation of 5 to pass within-batch variation, and don't put yellow's 5 onto cyan, magenta, and black. | Leave the wrong number standing |
| What to leave | The report must say it is within-batch variation, which two sheets were compared, the ΔEab, and the measuring conditions. A lone 4 is not enough. | Leave only a line that says pass |
Check before you measure
- Confirm you are comparing two sheets of the job, not against the signed proof.
- Read cyan, magenta, and black against the common limit of 4.
- If the conditions differ, don't calculate.
