GMI Process Control and Documentation 2 — Questions and Answers
Question 1: In graphic arts production, what is the primary purpose of a press fingerprint test?
- To measure ink viscosity
- To characterize how a press reproduces tone values under specific conditions (Correct answer)
- To calibrate the CTP platesetter
- To verify paper grain direction
Correct answer: To characterize how a press reproduces tone values under specific conditions
A press fingerprint establishes the tonal response and dot gain behavior of a specific press under defined conditions.
Question 2: Which ISO standard specifically addresses graphic technology process control for offset lithographic printing?
- ISO 9001
- ISO 12647-2 (Correct answer)
- ISO 15930
- ISO 13655
Correct answer: ISO 12647-2
ISO 12647-2 defines process parameters and tolerances for offset lithographic printing of halftone color separations.
Question 3: A solid ink density reading of 1.60 is measured but the target is 1.45. What corrective action should the press operator take first?
- Increase impression pressure
- Reduce ink feed to lower the ink film thickness (Correct answer)
- Increase fountain solution flow
- Change to a different ink brand
Correct answer: Reduce ink feed to lower the ink film thickness
Solid ink density above target indicates too much ink on the substrate; reducing ink feed lowers the ink film thickness to bring density back to target.
Question 4: What does TVI (Tone Value Increase) measure in print production?
- The increase in paper brightness after printing
- The difference between measured dot area and nominal dot area in print (Correct answer)
- The rate of ink drying on substrate
- The variation in registration across a press sheet
Correct answer: The difference between measured dot area and nominal dot area in print
TVI (also called dot gain) measures the difference between the printed dot area and the original file dot percentage.
Question 5: A job order traveler in a print shop is BEST described as:
- A document listing employee work schedules
- A document that accompanies a job through production tracking all specifications and sign-offs (Correct answer)
- A customer-facing invoice for services rendered
- A proof approval form signed by the client
Correct answer: A document that accompanies a job through production tracking all specifications and sign-offs
A job traveler (or job ticket) follows a job through every production stage, recording specifications, instructions, and operator approvals.
Question 6: During flexographic printing, which control strip element is used to monitor ink trapping?
- A star target
- Overprint patches showing two-color solids and their trap percentage (Correct answer)
- A slur gauge
- A resolution target
Correct answer: Overprint patches showing two-color solids and their trap percentage
Overprint patches in a control strip allow calculation of ink trapping by comparing two-color overprint density to individual ink densities.
Question 7: What is the function of a GRACoL characterization dataset in press calibration?
- It defines the paper smoothness targets for US sheetfed offset
- It provides reference measurement data used to create ICC profiles for US commercial offset printing (Correct answer)
- It specifies the maximum permitted ink viscosity for web presses
- It establishes recommended dot gain curves for flexographic printing
Correct answer: It provides reference measurement data used to create ICC profiles for US commercial offset printing
GRACoL characterization data (e.g., CGATS TR006) provides spectral measurement targets used to build ICC profiles for US commercial sheetfed offset printing.
GMI Process Control and Documentation 2
In graphic arts production, what is the primary purpose of a press fingerprint test?