Encostive

• costive: constipated

• encaustum: (Latin) purple-red ink

• encaustic: (adj) having the colours burned in; (n) an ancient method of painting in melted wax

• cost: a term from economics, implying that Shem writes for money

• does encostive ink mean "ink made from shit"? because this is clearly a reference to the haunted inkbottle image from Chapter I.vii where Shem does just that.