Decal paper or as it is commonly called gummed, designed for applying images on the ceramic surface (so-called hot decal) or on softer materials (cold decal).
In this case, the paper acts as a translation, which is applied to a manufactured product.
The process of printing an image on gummed paper is standard and does not differ from the usual one.
It is only worth mentioning that decal paper for inkjet printers is not very suitable, the image can come out poor quality. Also, you should use water-resistant ink.
For maximum results (in this case, image quality), you should use special laser printers for printing on decal paper. Then you won’t be inconvenienced by a failed image transfer.
What is decal paper?
Состоит данный вид бумаги из двух слоев: нижняя подложка (твердая бумажная основа) и верхний слой, который представляет из себя прочную пленку с очень маленькой толщиной. Часто этот слой делается на основе желатина и легко снимается водой.
Cold decal, which is suitable for softer materials such as wood, glass, plastic, etc. differs from hot decal only in that it does not need to be baked under high temperatures.
But there is a disadvantage of cold decal – the applied pattern is short-lived and under the influence of mechanical action can be damaged and “get off”.
Hot decal on the contrary turns out to be extremely durable. The picture, produced by this method, does not scratch and does not come off for many years. It is applied to ceramics or metal.
The image process
Холодная деколь позволяет декорировать такие нежные поверхности, как гладкую поверхность фруктов или овощей, лепестки цветов, свечи, ногти, пластик и даже кожу. Он основан на растворении желатиновой пленки и аккуратного переноса этой пленки на требуемую поверхность.
When water hits the gelatin layer, it dissolves and a thin layer can be lifted off the paper and stuck onto the product. In this case, the thin film repeats the texture of the pasted surface, which looks quite interesting.
It is desirable to maintain a temperature of 22 – 25 ° C and a relative humidity of 60% in the working room in order to perform the necessary color matching and increase the stability of paper sizes when printing.
It is the humidity that most strongly affects the stability of paper size.
Domestic paper usually has a lower dimensional stability and this is reflected in its curl and warpage at the edges.
If decal paper begins to curl, it is the first sign of not enough quality, or not the right climatic conditions for storage.
Consider the method of applying a hot decal. After printing the image, an even layer of varnish is applied to the paper.
A special decal mounting varnish is used.
It allows the design to hold firmly and not burn out during the subsequent heat treatment. After drying, cut out the desired image and place it in warm water for about 20 seconds.
After that, the blank with the image is taken out and glued to the ceramic surface with the paper layer down.
After all the procedures, we put the product in a special oven, which bakes the image at 800 ° C. After cooling, the product is ready for use.
Mounting decal varnish plays the role of a reinforcing film and is necessary for the reliable transfer of an image that has a complex outline or is made of many unconnected fragments. After mounting or drying, the mounting varnish is removed or burned off by firing.