Printing technology for flexible packaging materials has evolved significantly the past few years. Based on the required material quantity needed each time, customers can choose between several ways to print their packaging materials. There is a digital printing, offset printing, flexographic printing, rotogravure printing etc.
Most common and competitive printing ways for flexible packaging are flexography and rotogravure. In our company, we have the ability of providing flexible packaging materials printed in both these ways. A general rule for choosing the correct printing technology is based on the quantity of the order. Small to medium print runs are usually printed in flexography while on the contrary medium to long print runs are printed in rotogravure. Here in A. Hatzopoulos SA, we are committed in providing high level services and dedicated to maintain and expand our capabilities and expertise in order to meet the ever-diversifying needs of customers. So in order to reassure the best printing results in every rotogravure print run, we are applying the strictest quality control specifications even from the preprint stage. Our prepress team is responsible, among others, for transforming the artworks provided by customers in printable version using specialized software. This process includes the color separation based on specifications and issuing and sending the digital print proof. After final approval from the customers, we proceed in cylinder engraving and final production. This procedure makes each artwork perfectly printable, reassuring a high quality printing result.
Specifically, some specifications that each artwork needs to meet for a successful rotogravure printing process are the following:
-Use of as few colors as possible, fact which will provide cost optimization. Either way through, we are able to print up to 10 colors per artwork.
-Minimum text thickness (positive and negative): 0.14mm, this is needed to reassure that the texts will be readable and the cylinders will be correctly engraved. Additionally the space between texts needs to be at minimum 0,11mm.
-Barcode: Minimum magnification 80%, bar width reduction: 0, Type: EAN13-EAN8-UPCE-UPC A, this specification is absolutely necessary so the packaging will have a readable barcode and no problems to occur when final product enters the market.
-When negative texts are planned to be printed with CMYK background, an outline around them is needed so to reassure perfect color registration.
-Trapping effect. All elements with big color contrasts with the background must have an outline-overlapping, so the printing result does not contain shadows and gaps.
Taking all the above into consideration, when it comes to the question if there are any limitations in rotogravure printing tech, the answer is NO. Meeting only some key tips will provide us an excellent production. On our next newsletter, read, prepress guidelines for flexography.