Once you have decided to decorate your wine bottles with pressure-sensitive labels, there are a number of functional issues you need to take into account before you choose the mate
David Torley Avery Dennison Roll Materials Europe
Once you have decided to take the plunge and decorate your wine bottles with pressure-sensitive labels, there are a number of functional issues you need to take into account before you choose the material to use.
While the visual aspects of your label, and of your brand, are entirely between you and your print designer, it should be remembered that most of the pressure-sensitive label materials that confer a ‘traditional’ appearance to wine bottles are highly textured. The quality of the print results will therefore be dependent upon the printing technology employed, and the best results are obtained with printing techniques that deliver a soft impression on the paper. The optimal choice in this respect is offset lithography, but there are only a limited number of printers with rotary offset litho presses capable of running pressure- sensitive labels. Much more common is UV-cured flexography – and here, the printer needs to have a clear understanding of the nature of the materials being used, and to adjust the printing plate accordingly to achieve a quality result.
Choosing the right material
On the label material side specifically there are two main issues to take into account for wine labels, no matter what the design.
Good red wines can be laid down in cellar storage for a long time, at a likely temperature between 6 and 12 deg C. This can cause dampness. Paper is a natural material, and susceptible to attack by fungi and bacteria. For labels on bottles of red wine that may be stored for long periods, therefore, you should ensure that the label paper you use is protected with a fungicide and/or mould inhibitors.
In terms of adhesive choice, rubber-based adhesives are generally more resistant to fungal attack, although most water-based adhesives currently available are also perfectly adequate in this respect.
Standard machine-coated paper grades often used today in low-cost applications will discolour under long-term storage conditions, but are fine for rapid-turnaround brands that pass through a room temperature supply chain.
Ice bucket performance
With white wines, the most important criterion for the label is its ability to withstand immersion in an ice bucket – especially in the restaurant trade. There is no industry standard test method here, but in general pressure-sensitive labels perform better than traditional wet glue because the label edges are firmly adhered to the bottle substrate, thus slowing down the opportunity for water to penetrate behind the label.
To check the quality of the ‘ice bucket performance’, it is recommended that bottles filled with either water or wine are labelled with printed labels, and then allowed to condition for 24 hours. They can then be immersed in a water/ice mixture, and their ‘stickability’ assessed after 20 mins, one hour, and two hours. The label must remain adhered to the bottle for at least two hours, and during this period should not slip across the surface if pressure is applied. There should also be no edge-lifting of the label during the two hour period.
The final visual inspection is down to you. All paper labels will show some visual deterioration after this test, and the level of acceptability is subjective. To improve resistance to water penetration there are papers available with either barrier coatings on the back of the label facestock, or a film extrusion layer between label paper and adhesive. Your label supplier can confirm whether or not the paper you have chosen has this capability.
Clear film labels for the ‘no label look’
To ensure that there is absolutely no visual impact of water immersion, plastic film pressure-sensitive labels printed on a plastic film labelstock can be specified. They are often seen on beer or vodka bottles, which are also subjected to an ‘icy’ environment. With film labels comes the opportunity for creating the ‘no label look’ achieved with clear film labelstocks. This gives label designers a high degree of freedom to do something a little more avant-garde with a brand.
With the above information, and a clear briefing of your exact requirements in relation to a particular wine, your label designer, labelstock supplier, and label printer can be relied upon to deliver an excellent result.
For further information on self-adhesive wine labelling, advice, samples and technical know-how contact Glyn Scriven or David Torley
1 October 2011