Consumables
Updated Mottling guide for printers
Friday 13. June 2008 - Sappi has reinforced its range of practical information for printers by updating its technical guide: 'Mottling - Mottled impression' covering the common fault in offset printing where the printed image becomes marbled, speckled or blotchy. Part of the Sappi technical series, the 20-page practical guide describes the different types of mottling, how printers can identify its causes and how to remedy them.
“Mottling is often overlooked, as printers focus on preventing or eliminating more prominent problems in the printing process,” says Han Haan, Sappi’s Technical and Development Manager at Sappi in Europe. “But demand for quality has grown enormously over the last few years. Longer presses are widely used today, either for straight printing or perfecting, and when large numbers of colours or coatings are processed, the technical complexities increase steeply. Clients expect a uniform and even impression and faults in the printed image are no longer acceptable.”
Intensive testing by Sappi, in conjunction with Heidelberg, Flint and BASF, has shown that the causes of mottling depend on the choice or quality of the paper, the ink and fountain solutions, the screen used, as well as the press settings. The guide covers backtrap mottling, water interference mottling, screen (midtone) mottling, paper surface mottling and other causes, as well as Sappi’s own test procedures to ensure the printability of its papers.
The Mottling guide, revised and edited by product specialist Anton Albert at Sappi’s Gratkorn Mill, is one of ten technical publications available in Sappi’s Knowledge Bank aimed at helping printers achieve the best printed results. Other titles include: Adhesive Techniques, Processing Matt Papers, Folding and Creasing, Climate and Paper; Paper, Ink and Press Chemistry; On-Press Troubleshooting; Paper Standards and Measurements; and the Printing and the Papermaking Processes.
The new Mottling guide, as well as the other titles, can be ordered on the Sappi stand at Drupa (Stand 6B40), as well as at www.sappi.com/KnowledgeBank.
Sappi is the worlds leading producer of coated fine paper. Its brands include Magno, HannoArt, Tempo, Quatro and Royal graphic papers, as well as Algro, Leine and Parade speciality labelling and packaging papers and boards. Customers in more than 100 countries worldwide specify these for the highest quality publishing, promotional and packaging applications. The papers are produced in mills accredited with ISO 9001, 14001 and EMAS certification and Sappi is the first paper company in Europe to hold chain-of-custody certification for its entire European operations under both the Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forest Certification (PEFC) schemes.
1. ‘Mottling – Mottled Impression’: the latest publication in Sappi’s technical series.
2. Sappi’s Technical and Development Manager, Han Haan, says the aim of the updated guide is to help printers achieve the best quality results.