• First level: security features that can be easily observed with the human eye: fine line prints, guilloche patterns, special line weaves, shaded text, Salvadoran coat-of-arms, unique and sequential numbering, holographic lamination, watermark, cameo effect, interlaced picture, data and signature
我 辦公室 裡 的 一個 同事 專門 負責 做 音樂 的 客戶MultiUn MultiUn