ITR (In The Round) or seamless photopolymer plates have been used for some time by printers in order to meet the exacting needs of their clients or to achieve the high-speed capacity of their printing presses.

Emanuel Narainsamy, Polyflex’s Plate Production Manager, reports an increase in demand for ITR plates and he ascribes this to the excellent print results and press speeds that flexo printers are reporting. Traditionally many brand owners thought that a seamless design had to be committed to gravure printing with its engraved cylinders. However, this isn’t the case.

To give the technical background, whilst ITR plates are ideal for a seamless design, they also allow for tight register and fine detail designs with tight register. They are also appropriate for faster press speeds. The artwork is directly imaged onto the extruded photopolymer plate, which in effect means that plate mounting takes place outside the press. Flexo printed artwork is normally distorted to allow for the plate gap and the curvature of the plate after mounting. However, with ITR sleeves, no distortion is required.

Customers have realised that if they want a repeat pattern across their flexible packaging, there is a significant cost saving to a seamless plate for the background patterns and colours. Examples are many sweet wrappers and condiment sachets. The variable design elements can then be printed with conventional plates.

In summary, the advantages of ITR plates are:

• High-quality ink transfer with solvent-based, water-based, or U.V curable inks.
• Excellent print quality and low dot gain without distortion and skew errors.
• Easy and safe mounting allows quick turn-around time.