One potential problem in pressing is called ghosting or shadowing. This is where the center of the part seems to have a darker section or where it looks different than the edges of the part.
This type of manufacturing defect can be fixed by adjusting the settings and is not a vinyl or glue issue.
Essentially ghosting is caused by a change in the surface texture. This is caused by the vinyl becoming over stretched on the edges and the center part of the component which is discolored is a section of the vinyl that was not stretched at the same rate as the other areas.
Typically this issue only happens on membrane presses and not on vacuum presses. The reason is that the membrane is trapping the vinyl down to the door. Raising the membrane for a vac to get the vinyl stretching evenly then lowering the membrane to finish up the detail. Various presses have different functions so this needs to be discussed.
In cases where your membrane press does not have the ability to raise the membrane for a vac stage you can try to move the parts further from each other. This gives more vinyl between each component and can reduce the over stretching.
If both cases above do not work please feel free to contact your laminate sales rep and they will get a tech expert to help fix the issue. It can be solved.
Example of ghosting (note the gloss level change halfway down the image)