Endoscopic procedures yield small pinched off tissue samples and are commonly used for biopsies of the gastrointestinal tract. The specimens obtained from endoscopy will most likely be of small dimensions with difficult to see cut edges.
It is unlikely that any inked surfaces will be present. In fact, the entire specimen is often colored with eosin to make it more visible.
Since the surface will likely appear homogeneous, you will embed these types of biopsies most often on end, so that the tallest side is traveling into the block interior. This allows the greatest number of sections to be obtained from the tiny specimens for multiple levels, special stains, and immunohistochemistry (IHC).
Since multiple level section protocols are very common with these types of biopsies, select the smallest mold size that appropriately contains the specimen pieces.