Which factor can cause ink to skip on polyester film?

The correct answer relates to the physical interaction between the ink and the substrate, in this case, polyester film. When erasing is done with excessive pressure, it can create a smooth, glossy surface that may unintentionally remove or disturb the ink layer. This disruption can lead to areas where the ink has been compromised, causing the ink to skip during application.

The texture and finish of polyester film mean that certain erasing techniques can smooth out the surface too much, affecting the ink's ability to adhere properly on subsequent applications. As a result, when the ink is applied to these areas, it may not flow consistently, leading to skipping.

In contrast, excessive sunlight exposure, using an incorrect type of ink, or applying the ink too quickly may lead to other issues, such as fading, drying problems, or inconsistent application, but they do not directly impact the physical disruption of the layer due to erasing practices. This highlights the importance of applying the correct technique when working with specific substrates to achieve optimal results.