Printing Processes

Screen Printing

Screen printing is used to print a variety of products, especially those with large print areas where a good coverage of ink is required, for example; bags, folders, umbrellas etc.

A screen is made of a piece of porous, finely woven fabric usually nylon or polyester. The screen (or mesh) is stretched over a frame of aluminum or wood. Areas of the screen are coated or masked off with a non-permeable material to form a stencil, which is a negative of the image to be printed, the areas of the screen that aren’t coated allow ink to pass through.

The screen is placed over the product to be printed, a flood bar and ink is then passed over the entire screen to fill the mesh openings with ink. A squeegee (rubber blade) is then passed over the screen and pushes the ink through the open mesh leaving a printed image on the product.

Pad Printing

Pad printing is used to apply a printed image to a 3-D product.

Pad printing is achieved by transferring an image from a printing plate via a silicone pad and on to a product. Ink is applied with a squeegee to the etched image area of the printing plate filling it with ink, the top layer of ink becomes tacky as soon as it is exposed to the air, the transfer pad presses down onto the printing plate, the pad is compressed and pushes air outwards causing the ink to lift from the etched image area and adhere on to the transfer pad. The pad then moves over and compresses down on to the product surface, transferring the ink from the pad to the product.

Laser Engraving

Laser engraving is used to engrave or mark metal, wood and some plastic products.

The artwork is loaded into a computer programme which controls a laser. The laser then passes over the product and either vaporizes of fractures the surface layer to create an engraving. The lasers focal point is less than a fraction of a millimeter, allowing for fine details in complicated and intricate designs to be achieved.

Litho Printing

Lithographic printing is used for printing paper products such as note pads and sticky notes.

A piece of film produced from artwork is placed on to a flexible aluminium plate covered with a photosensitive emulsion and is exposed to ultraviolet light. When the plate is developed it shows a reverse image of the original (positive) image, this image is the exposed emulsion that remains on the plate after developing.

The plate is fixed to a cylinder on a printing press. Dampening rollers apply water to the blank parts of the plate, water is repelled from the emulsion of the image area. Ink is then applied to the plate by inking rollers, the ink is repelled by the water and only adheres to the emulsion of the image area. The inked plate then rolls against a cylinder covered with a rubber blanket, which squeezes away the water, picks up the ink from the plate then transfers the image to the paper as it rolls across the blanket drum.

Transfer Printing

Heat transfer printing is used to produce high quality single, multi colour or 4 colour process images on a variety of fabric and nylon products. Transfer printing is the recommended print method for reproducing any designs that incorporate tints of a solid colour.

The heat transfer process uses a specially coated carrier paper on which a design is printed, the carrier paper is then place on to the product surface and when heat and pressure is applied to the carrier paper by means of a heat press, the ink (image) is transferred on to the product.

Foil Blocking / Blind Embossing

Diaries and various leather products can be branded using either foil blocking or blind embossing.

A block is made usually of metal or wood bearing the image to be printed in relief. The block is then mounted to the print head of a machine which applies heat to the block. Coloured foil is placed over the area of the product to be embossed and under pressure the block and product are then brought together. The combination of heat and pressure releases the pigment from the foil and transfers the image to the products surface.

Foil is available in gold and silver as standard, other colours are available.

Blind embossing uses the same process as foil blocking, but without the use of foil.