For some time the two brands were produced together; the [[Mentmore]] was transformed into a joint stock company in [[1930]]. The situation at that time is not clear, there are those who reported that the brand [[Mentmore]] has been progressively replaced by [[Platignum]], but by the late '30s to the' 50s, there is a large production of pens with this brand . Also a patent of 1936 ({{Cite patent|GB|457212}}) explicitly shows the name of ''Spot Pen Company'' as the new name of ''Mentmore Manufacturing Company''. | For some time the two brands were produced together; the [[Mentmore]] was transformed into a joint stock company in [[1930]]. The situation at that time is not clear, there are those who reported that the brand [[Mentmore]] has been progressively replaced by [[Platignum]], but by the late '30s to the' 50s, there is a large production of pens with this brand . Also a patent of 1936 ({{Cite patent|GB|457212}}) explicitly shows the name of ''Spot Pen Company'' as the new name of ''Mentmore Manufacturing Company''. |