Lamination of your graphics is not always necessary. Digitally printed solvent graphics and screen printed graphics are water proof and light fast even without lamination. However, lamination will add to the light fastness of the inks for long term graphics and protects against abrasion and chemical damage. There are a wide variety of types and finishes of laminates available.
Indoor graphics are more typically laminated with a 3 or 4 mil clear, calendared, “luster” laminate. These laminates are typically guaranteed for 2 –3 years indoors, which is usually well beyond when most customers intend to still be using the graphics. These laminates provide some limited UV protection and abrasion resistance, as well as limited chemical resistance. The “luster” finish is most often selected for indoor graphics as it cuts the glare from indoor lighting which can obscure the image. Synonyms for “luster” include the terms, “satin” and “semi-Matte”. All these terms denote a finish that is somewhere between a gloss and a matte finish.