rubber stamp vs sealskin

rubber stamp

noun
  • A piece of rubber or similar material with a design or text carved or molded for the purpose of transferring ink or dye to imprint that design on another object. 

  • A person or organisation that approves, routinely or as a formality, matters decided by some other person or organisation. 

adj
  • Of a person, organisation, or process, making decisions or approving matters routinely or without real power. 

verb
  • To process, approve or decide matters routinely rather than through careful consideration. 

sealskin

noun
  • An item of clothing made from sealskin (whether real or imitation). 

  • A type of fabric made from the skin of seals. 

  • Any fabric manufactured to resemble sealskin. 

How often have the words rubber stamp and sealskin occurred in a corpus of books? (source: Google Ngram Viewer )