The election authorities shall prepare full instructions for the guidance of voters at each election as to obtaining ballots, as to the manner of marking them and the method of gaining assistance and as to obtaining new ballots in place of those accidentally spoiled; and they shall respectively cause the same to be printed in large, clear type, on separate cards, to be called cards of instruction; and the election authorities shall furnish to the judges of election a sufficient number of such cards of instruction to enable the judges of election to comply with the provisions of this article.