Computer Colour Matching Questions and Answers

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: lot-to-lot strength variation must be fed back into the database, while price changes affect only the ranking of candidates and not the physics of the prediction. Statement 3 confuses the software with the data - the database describes the colourants on the substrate and survives a change of program version.

Answer: B

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the mechanism. A dye lot ten per cent stronger than the calibration will make every recipe containing it come out too deep, and the error is systematic rather than random. Checking strength on receipt against a reference and applying a correction factor is the standard defence.

Answer: C

It is determined by dyeing the new lot and comparing against the stored data. Applying it avoids recalibrating the whole colourant from scratch. The factor is found by a single dyeing. Full recalibration is thereby avoided.

Answer: D

Very pale and very deep shades are where the approximations are weakest. Additional calibration points at the extremes improve matters somewhat. Mid depth shades predict best of all. Both extremes are harder for different reasons.

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 identify the two difficult ends. At very pale depths a tiny absolute error in dye weight is a large proportional one, so the shade moves noticeably; at very deep depths the linearity between \( K/S \) and concentration fails. Statement 3 is contradicted by both - accuracy is best in the middle of the range.

Answer: B

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the mechanism. A recipe calling for 0.02 per cent of a dye is thrown out by a weighing error that would be negligible in a two per cent recipe, and pale shades are also the ones in which small colour differences are most visible. Dispensing accuracy, not prediction, is usually the limiting factor here.

Answer: C

Correct answer: a recipe correctly predicted must still be correctly weighed out

The prediction is only as good as its execution. If the software calls for 0.35 per cent and the dispenser delivers 0.38, the batch will not match however sound the calculation was. This is why automated dispensing systems and right-first-time performance are discussed together - they are two halves of the same objective.

Answer: D

Both are true and the reason gives the benefit, and pale shades gain most from it. The prediction and the dispensing are separate sources of error. Both must be right for a successful dyeing. Either can spoil the result on its own.

Answer: A

Correct answer: a correctly measured and verified standard

A sound standard is a precondition for success, not a cause of failure. The other three are the usual culprits when a first shot misses: a database that no longer describes the current dyes and substrate, dispensing that does not deliver what the recipe asked for, and a dye lot of unexpected strength.

Answer: B

Correct answer: a recipe matched in the laboratory may need adjustment in bulk

Liquor ratio, agitation, heating rate and machine type all differ between a laboratory dyeing and a production batch, and dyes exhaust differently under those conditions. A correction factor between laboratory and bulk is established empirically for each machine and process, and it must be maintained just as the database is.