What is cockling?
Cockling, plain and simple, is the distortion of paper by the way of ripples or wrinkles in areas of high ink coverage. The problem is practically impossible to rectify and the best way around it, if it does happen, is to stop it from happening in the first place! In fact cockling can be so much of a problem that it can interfere with the printing process- even causing the paper to be scratched by the printhead(s).
What causes cockling?
There are a number of scenarios that can cause cockling. The number one cause of cockling we see is caused by the printing process, by using too much of an ink load on paper that is not up to the job. It is during the drying process that the excess ink causes the fibres in the paper to expand, causing the cockling.
Moisture and humidity can cause cockling and it is advisable to run a de-humidifier in the area you store your paper, to guard against excess moisture being absorbed by the paper. However, for the purpose of this post we are looking at cockling caused by the print process.
What to do about it, if you are getting cockling?
Use a heavier weight of paper. There is a limit to how much ink a light weight paper can take. If you are printing using deep, rick colours, or heavy blacks, the ink usage will naturally be high. You will need to use a paper that can accommodate that sort of ink usage.
Use a coated paper. Look for a good coated paper. These papers can accept heavy ink loads and still not cockle. In fact our Matt Barrier coated paper can take up to 400% ink load without cockling!
Paper weight choice can be a minefield, so here is a shortened list to give you an idea of the weight to choose for your job:
80gsm uncoated - just for black line drawings
90gsm uncoated – just for mono or colour line drawings
100gsm Coated – presentation line drawings and wall charts or light coverage gift wrap
120-140gsm Coated – presentation heavier fills
165-180gsm Coated – full coverage posters
230gsm Coated – full coverage high quality prints and art posters
300gsm Coated – like a heavy card usually for framed art prints
Satin or Gloss 190gsm – for high quality low cost photographic
Satin & Gloss 260gsm – for photographic best quality