Art For Screenprinting
The original 'art' or design' to be printed can come in many forms, but must eventually be converted to a stencil image on the screen. In screen printing, only one colour can be printed at one time, and so multi-coloured print jobs require a separate piece of film to create each colour's stencil.
When we talk about art for screen printing, we really mean 3 different things:
#1 The Original Art or Design
Can be in the form of a sketch, a layout on a computer, a painting or drawing, a typewritten rough, or a finished camera-ready design.
From this original you can determine what you are going to print, the size, location on the substrate, and number of colours required to reproduce the image.
Decide at this point if the art is reproduceable or usable for screen printing.
#2 Mechanical Art
This is an interim step where the elements of the design are composed or laid out with proper type, artwork is changed to camera ready images, or scanned as digital information in a computer. At the end of this stage, all design elements are in place relative to each other, colours have been separated to individual overlays or plates, in register, and trapping considerations where colours meet have been built in. The term 'camera ready' is used to describe the art at the end of this step.
The term mechanical art refers to the physical re-scaling and building of the separate colour plates, with type and halftoned photos. In the old days of paste-up and camera shots, this was done as separate steps, and then layed out on a board or overlays.
#3 Film Positive
A film positive carries an opaque image on a transparent film which is identical to the image to be printed. The film is used to make a stencil.
Let's look at each step...
ORIGINAL ART OR DESIGN
- Line drawings (or line art, which is art or type with no tonal shading) should be in black on white, irregardless of the final colour.
- Photos or works of art need to be scanned (digitalized) to prepare them for conversion to halftone art, or separation for printing process colour.
NOTE: To reproduce tonal variations in most types of printing, it is neccessary to convert the greyscales of continuous tone photos to a screen of small dots. Depending on the tonal value of an area, the dots are smaller or larger or more concentrated. One of the major drawbacks to screen printing compared to other printing methods is its physical limitations in the reproduction of fine halftone dots.
