Plastic Plus

#Signs, notations, symbols #Quadrilaterals #Letters presenting a special form of writing #Colours #Mathematical signs combined with figures or letters #One quadrilateral #Quadrilaterals containing one or more letters #Letters containing written or typographical matter #Series of letters presenting different forms of writing #Series of letters in different dimensions #Letters underlined, overlined, framed or barred by one or more strokes #Letters in light-coloured characters on a dark background #Two predominant colours