GMI Ink & Substrate Interaction 1

Question 1

Which substrate property most directly affects the rate at which ink is absorbed after printing?

Accepted Answer

Porosity

Answer

Porosity determines how quickly and deeply ink penetrates a substrate's fiber structure, directly controlling absorption rate.

Question 2

In the context of offset lithography, what does 'ink tack' refer to?

Accepted Answer

The resistance of ink to splitting between surfaces

Answer

Ink tack is the resistance to splitting that occurs when the ink film is pulled apart between the plate, blanket, and substrate surfaces.

Question 3

What phenomenon occurs when ink laid down in a later printing unit fails to adhere properly to ink already printed by an earlier unit?

Accepted Answer

Poor ink trapping

Answer

Poor ink trapping happens when a subsequent ink color does not properly adhere to a previously printed ink layer, causing color shifts and density loss.

Question 4

Coated papers generally produce smaller printed dot sizes compared to uncoated papers because:

Accepted Answer

The coating layer reduces ink absorption and lateral spread

Answer

The smooth, non-porous coating layer prevents ink from spreading laterally into the substrate, resulting in sharper, more controlled dot reproduction.

Question 5

Surface energy of a substrate is measured in which units?

Accepted Answer

Dynes per centimeter (dyn/cm)

Answer

Surface energy is measured in dynes per centimeter (dyn/cm), indicating the substrate's ability to be wetted by inks and coatings.

(GMI) Graphic Measures International Certification Practice Test

(GMI) Graphic Measures International Certification Practice Test

GMI Ink & Substrate Interaction 1