特とく厚あつ口ぐち

noun which may take the genitive case particle 'no', noun

extra-thick; heavyweight

Used especially for paper, cardstock, or similar sheet materials that are thicker than standard. Often appears in product descriptions or specifications.

• この名めい刺しは特とく厚あつ口ぐちの紙かみを使つかっています。

  This business card uses extra-thick paper.

• 特とく厚あつ口ぐちの封ふう筒とうは丈じょう夫ぶで郵ゆう送そうに適てきしている。

  Extra-thick envelopes are sturdy and suitable for mailing.