Colour Proofs What did we learn about colours?

Additive Primaries What are these primary colours? The combination of all three colours when added together produces white light. When two additive colours are added together they produce a subtractive colour.

Subtractive Primaries In the same way two subtractive primaries will produce an additive primary? The three subtractive colours make black.

Why use these colours? It would be unrealistic to pass a picture with millions of colours through the printing press millions of times to print each colour. The image is separated into its constituent primary colours. Then a metal printing plate is made for each primary colour. The image is made from printing each colour one on top of the other in the exact position.

Printing When it comes to publishing it is important to remember that colour is modified by the light. Paper does not emanate (give out) light. The material on the page is able to absorb parts of the white light (subtracting parts of the daylight coming in), and then the eye perceives the colour being reflected after the others have been absorbed.

Printing Printers have developed a model whereby it is based on the three subtractive primary colours, cyan, magenta and yellow. In theory these colours can produce other colours and all three can produce “black”. Then why do we use black as a fourth colour?  In theory all three colours produce “black”, but in reality, the colours appear to produce a dark brown. Therefore, black is the Key colour that is added last to give the image its definition.

Proof Proofs enable you to approve stages in the production of your job, or if necessary, to request changes to the design. You should always see a proof of the finished artwork before passing it for printing.

Proof So you have been asked what sort of proof you would like? Confused? The following is a list of proofs and terms used in the creative-pre-press department. The kind of proof required may depend on the elements of the job that need to be checked, such as colour quality, trapping, overprinting and registration. Time and budget constraints influence the extent of the proofing stage and the type of device employed.

Proof There are various kinds of proofs that will suit particular stages. Whilst the design is being produced on the computer, a laser or ink jet printer will enable you to check that all the copy is present, in the correct position, and that tints and colours are as specified. At this stage if changes need to be made they will be relatively inexpensive. Changes later on will add to the bill for printing. Once the design is complete and the files have gone to the Repro House or Printer, supplying laser proofs will verify what the job should look like.

Proof Alternatively, designers nowadays will supply hard copy proof in the PDF format. The file can be transmitted electronically: saving time and money.

Task: Answer the following:

Proof Digital Colour Proof This is the most popular form of colour proofing, when the content and basic layout has been approved. With digital colour proofs you will get a reasonably accurate colour match. A very good system if you are requiring more than one proof to circulate before creating the films.

Film FILM involves photo-sensitised acetate sheets which are processed through an exposure to light. The film carries the images to be printed. The acetate sheets are solid black before exposure. After exposure, the image areas become clear. The film is first used to make proofs and then, secondly, used to make the metal printing plates.

Film Proofs Film proofs are created using a positive or negative film which has been outputted from an imagesetter. They are highly accurate representations of what the final printed product will look like. They are given to clients for final review, approval, and "sign-off" before the printing plates are made and the order is put on the press. An example of a film proof is a Chromalin.

Proof Chromalin Proofs These proofs offer a wide range of colours and are the most faithful reproduction short of a press proof. They are composed of separate layers of coloured dye powders or toner adhering to a carrier sheet. They are produced from the actual film negatives or positives. These are the most expensive proofs.

Proof Press Proofs Press proofs are printed samples that show exactly what a job will look like when it comes off the press. Because the choice of paper and ink introduce a variable known as press gain, press proofs are used to determine how much effect the ink will have. This method of proofing, however, is time consuming and can be very expensive.

Task: Please answer the following: What do two additive colours added together produce? When two additive colours are added together they produce a _________ colour. Why are these colours used? Does paper emanate light?

Task:Continued Printers have produced a model based on three subtractive primary colours, what are they? ________ ________ ________ What is the common colour that these three produce? __________ What do ‘proofs’ enable you to do? What should happen to finished artwork before passing it for printing?

Task: Continued: Name 4 elements of a proofing job that need to be checked: 1. _____________ 2. _____________ 3. _______________ 4. _______________ Whilst a design is being produced on a computer, what will enable you to check that all the copy is present, in the correct position, and that tints and colours are as specified?

Task: Continued: Will any changes made at this point be expensive or inexpensive? When the design is complete where do the files go to? 1. _____________________ 2. ___________________________ What would be an alternative way of supplying hard copy? How would this be transmitted?

Task: Continued: What is the most popular form of colour proofing? _________ _________ ___________. What would be an alternative way of supplying hard copy? How would thi What does FILM involve? What does the film carry? What colour are the acetate sheets before exposure?

Task: Continued: What happens after exposure? What is an example of a film proof? What are they composed of? Are they the cheapest or most expensive type of proof? What are press proofs?