Roman pottery (Samian ware) and mould

I made this model after seeing Dani Wootton's excellent '5 Fascinating Finds' video on the Time Team channel https://youtu.be/m-Z1uM9DMRI This model illustrates Dani's description of how Roman pottery was mass produced using a mould with decorations pressed into the mould surface. Click on the annotations on the model for more information. In researching this model I visited the British Museum in London to get a closer look at the 'punches' that were used to create the decorative indentations in the mould surface. I felt sure the surface of the punch must be curved to follow the contour of the mould but wasn't sure if the curve was more pronounced so that the punch would be rocked back and forwards when being pressed into the clay. The example I saw at the British Museum (Ancient Rome room - display case 26 - see below) showed a punch with a figure on it and a slight convex curve which I think would have matched the surface of the mould.