Smart 31 Printer (Single/Dual Sided) SMART-31 Series Value Class ID Card Printer for Everyone. A perfect solution for printing ID cards at a low budget. SMART-31S (Single-Sided), SMART-31D (Dual-Sided) and SMART-31R (Rewritable) printer models are available. SMART-31R Rewritable printer is an ideal solution for printing temporary information on ID cards.