Polyjet technology uses liquid resins as printing material, as these allow a much finer layer thickness. During the printing process, the individual layers of the object are printed from bottom to top. A layer of material is applied and then cured with UV light. This means that the printer cannot print anything to which no drops of resin can "adhere". Support material is automatically printed at these points, on which the print material layer can be applied. In order to obtain a smooth construction surface, an additional layer of supporting material is produced before the model is printed on it.
Every part of the object that comes into contact with the support material appears matt after washing. Thus, the underside of each printed object is always matt, as is any negative slope and any spot vertically below a negative slope.
A hard edge can be seen at the transition from a negative gradient to a positive gradient, i.e. the area with support material to the rest of the object. At fluid transitions, such as an egg, it is particularly prominent. With a pyramid, however, the edge coincides with an edge of the object, which is why it is not noticeable.
If you select the 'Matt' option, a thin layer of support material is printed on each positive slope, so that no edge is created anywhere and the entire object becomes matt. However, this is associated with increased material consumption.
If you select the 'Glossy' option, the described edges appear at the transitions. If your object has an orientation in which this edge coincides with the edges of the object and you wish this, you can specify this orientation. However, a different orientation may also result in higher consumption of support material.