| Earth
Colours |
A
pigment of the class of pigments which are usually mixed directly
from the earth, dried and ground. They are frequently also termed
"natural pigments". Most earth pigments consist of complex
mixtures of iron or manganese oxides with aluminium silicates. Typical
examples are red and yellow oxides of iron, yellow ochre, raw sienna
and raw umber. |
| Effective
Resolution |
The
final appearance of a scan that has been enhanced to produce more
data than the scanner can record. This is done by interpolation. |
| Elastic
Limit |
The
point at which a mesh when under tension will no longer return to
its original size. |
| Elasticity |
This
term is sometimes used incorrectly in the context of an ink or varnish
film to describe its flexibility. In this sense its use is not recommended. |
| Electro-magnetic
Spectrum |
The
complete range of electromagnetic waves, as measured by wavelength.
Different wavelengths have different properties. These include sound,
radio, microwave, heat, light, ultra-violet, X-rays, cosmic rays. |
| Electronic
Dot Generation (EDG) |
Process
used in digital halftone production that allows negatives or plates
to be generated by grouping micro dots into regular groups to function
in the same manner as a photographically produced halftone. |
| Electrostatic |
A
process of imaging where a "toner" is used to form an
image by controlled static charges. Toner printing adheres to the
charged areas. |
| Elongation |
Measurement
of the amount of stretching. |
| |
Used
as a term with reference to screen printing mesh. It is the degree
to which a mesh will stretch and still return to its original size. |
| Emissive
Object |
An
object that emits light and/or other radiant energy, such as the
burning gasses of the sun or the heated filament of a light bulb. |
| Emulsion |
In scientific terminology this is an homogeneous material formed
by the incorporation of two liquids which are normally immiscible.
It is also the term applied to the photosensitive material used
to produce photopositives used in pad printing. In screen printing
the coating applied to the mesh during the creation of a stencil
is also known as the emulsion. |
| Emulsion
Side |
The
side of photographic film or paper coated with the light sensitive
silver halide emulsion. Film output is specified for use as emulsion
up, or emulsion down. |
| Enhancement |
The
improvement of an image either through colour and/or density change. |
| Etch |
To
remove metal by chemical or electrochemical means in order to produce
an image on a printing Plate. |
| Extender |
An
inorganic mixture in powder form which has little obliterating power,
but is used as a constituent of inks to adjust the properties of
the ink. A liquid material added to an ink to increase its transparency.
See also "Varnish". |
