GMI Troubleshooting & Problem Resolution 3

Question 1

A gravure print of a fine-screen tint shows missing dots in highlight areas on every other copy. The most likely cause is:

Accepted Answer

Worn or damaged doctor blade leaving residual ink in cells unevenly

Answer

A worn doctor blade can skip, leaving uneven ink in shallow highlight cells and causing every-other-copy dot skipping as the cylinder rotation pattern aligns.

Question 2

After replacing a printing plate, a pressman notices that register is off on the first unit only. The corrective action is to:

Accepted Answer

Adjust the plate's lateral and circumferential register on that unit

Answer

When only one unit is out of register after a plate change, the plate itself was mounted incorrectly and requires lateral/circumferential adjustment on that unit alone.

Question 3

A print shop receives customer artwork with text set in a light-weight sans-serif font at 6 pt. The most likely press-related problem is:

Accepted Answer

Ink spread causing fine strokes to fill in and become unreadable

Answer

Very fine strokes in small text are highly susceptible to ink spread (dot gain), causing hairline strokes to fill in and become unreadable on press.

Question 4

When measuring a printed neutral gray patch, a spectrophotometer reads a* = +3 and b* = −4. This indicates the gray has a:

Accepted Answer

Slight green cast with a blue shift

Answer

In CIELAB, a positive a* value means red shift and negative means green; a negative b* means blue shift — so a*=+3 and b*=−4 represents a slight green-blue cast.

Question 5

A flexo press operator notices that solid ink density is acceptable but halftone midtones are printing too dark. The most targeted correction is to:

Accepted Answer

Reduce plate impression pressure to lower mechanical dot gain

Answer

Excessive mechanical dot gain in midtones without affecting solid density points to too much impression pressure spreading halftone dots.

(GMI) Graphic Measures International Certification Practice Test

(GMI) Graphic Measures International Certification Practice Test

GMI Troubleshooting & Problem Resolution 3