Acid-free - A material when
tested using a surface probe or cold extraction is found to
have a pH of 7.0 to 9.5, indicating a material contains no
mobile or available acid ions for a chemical reaction. Over
time materials may naturally become acidic by absorption through
the atmosphere, or by coming in contact with acidic materials.
Acid Reducer – Any
product that when applied or added to a material neutralizes
acid content.
Acrylic - A fast-drying paint containing
pigment suspended in an acrylic polymer emulsion, exhibiting
varying levels of opacity or translucency. Acrylics are
water-soluble when wet, become an insoluble film when dry.
Acrylic paints may be made to be satin, high gloss or matte
finishes. Pigment amounts and particle size can alter the
paint sheen. Likewise, matting agents can be added to dull
the finish. Topcoats or varnishes may also be applied to
alter sheen.
Water or mild solvents do not re-solubilize
drying or dried acrylic paint, although isopropyl alcohol
can lift some fresh paint films. Toluene and acetone can
remove paint films, but they do not lift paint stains very
well and are not selective, not to mention, using toluene
and acetone are hazardous materials. The use of a solvent
to remove paint will result in removal of all of the paint
layers, acrylic gesso, etc.
Only a proper, artist-grade acrylic-gesso should be used
to prime canvas in preparation for painting with acrylic.
It is important to avoid adding non-stable or non-archival
elements to the gesso upon application. Acrylic will not
form a stable paint film if it has been thinned with more
than 30% water content. However, the viscosity of acrylic
can successfully be reduced by using suitable extenders
that maintain the integrity of the paint film. There are
retarders to prolong drying and workability time and a flow
release to increase color blending ability.
Forms: Bottle - A
light viscosity acrylic paint (about like light cream) that
may be used directly by pouring or brush, or mixed with
water or other mediums for thinner more transparent painting
effects. (USAQ offers acrylic paint in a bottle.)
Tubed – A medium
viscosity acrylic paint (about like toothpaste) that may
be mixed with water or other mediums for thinning to paint
with a brush, or used directly with a palette knife.
Jar – A thick
viscosity acrylic paint (about like spackle compound) that
may be mixed with water or other mediums for thinning to
paint with a brush, or used directly with a palette knife.
Additive - Any substance added to another
substance to alter or improve the properties.
Adhesive - Any compound
that can stick two surfaces together. Adhesives come in
a myriad of forms including liquid, solid, cement and paste.
(USAQ offers several adhesives, notably PPA, 101 Artist
Cements, Great Tape and Duo.)
Archival - 1. A non-technical term that
suggests a material is permanent, durable, or chemically
stable. 2. A material that can safely be used for preservation
purposes, although there are no quantifiable standards that
describe how long an archivally sound material will last.
Assemblage - A modern art term describing
objects collected and assembled together to create a harmonious
work of art. Generally, the 3-dimensional components are
preformed, not made by the artist, and not originally intended
to be used as an art material.
ATG – An economical pressure-sensitive
dry adhesive. ATG, applied by hand or mechanically dispensed,
is evenly distributed from a liner-paper. (USAQ’s
‘Great Tape’ is an ATG.)
Binder – A substance used to bind
or cement the pigment particles together in paintmaking.
Bleed - 1.The migration of ink, paint or
adhesive through or across paper. This process may occur
immediately upon application or over time. 2. A printer’s
term used to refer to color (ink, paint, or paper) that
runs all the way to the edge of a trimmed page.
Brilliance - A subjective term referring
to the cleanness or lack of a muddy or dirty tone in pigmented
coatings.
Bronze - An alloy of copper
and tin and sometimes other elements; also any copper-base
alloy containing other elements in place of tin.
Bronzing - A subjective name given to a
metal-like surface using nonmetallic colored materials.
Caking – The settling of pigment
particles into a near-solid mass, which is not easily re-dispersed
by stirring.
Caliper (Paper Thickness)
- The average thickness of a single sheet paper as determined
by measuring the thickness of different sheets and averaging
the results.
Coagulate – The thickening
or congealing of fluid.
Cockle - The formation
of ripples, bubbling or warped areas when paper is wet.
Cockling is caused by uneven moisture uptake or uneven tension
during drying.
Cold Pressed - Cold-pressed
watercolor paper has a lightly textured surface. Texturally,
it is somewhere in between rough and hot-pressed paper and
often preferred by watercolor artists for its’ ideal
absorbency.
Collage - An artistic collage
work may include newspaper clippings, ribbons, bits of colored
or hand-made papers, portions of other artwork, photographs,
and such, glued to a piece of paper or canvas. Derived from
the French "coller" meaning "glue",
this term was coined by both Georges Braque and Pablo Picasso
in the beginning of the 20th century when collage became
a distinctive part of modern art. (For more on collage techniques,
USAQ offers both videos and books on this subject.)
Colloidal dispersion –
A heterogeneous mixture where very small particles of one
substance are distributed evenly throughout another substance.
Color - A visual experience
that can be described as having quantifiable dimensions
of hue, saturation, and brightness or lightness, and does
not include aspects of size, shape, texture, or movement.
Color is immediate, drawing attention. A sharp contrast
in color draws even more.
Colorant - Any substance
that imparts color to another material or mixture. Colorants
may be dyes or pigments.
Colorfast – also
known as Lightfast – A term used to describe an object
or paint that resists the harmful UV rays of light, acid
and heat. A colorfast item is not impervious, but resists
all three.
Composition – Composition
refers to how the artist organizes the creative elements,
colors and shapes into a whole, one that is satisfying to
the viewer. Creative variables such as balance, color, and
texture are all subjective aesthetic considerations, that
when combined form an image that is pleasing to the eye.
The main element of composition is balance and the shape
of the unused (or negative) space, as well as element (positive
image) proportion. Composition may be balanced and symmetrical
or off-center or in asymmetrical balance.
Consistency - A harmonious
uniformity and ‘feel’ of a substance, combining
both the viscosity and rheology.
Crackle Medium –
Any medium that is made to alter the surface of paper or
paint, by creating fissures, crazing and crackling, thus
giving it an aged appearance. (USAQ offers this product
named 101 Craze & Crackle.)
Craze - A small defect
resembling an uneven tear in an acrylic film. Crazing may
occur when pourable or sprayed products are applied too
thickly in a single coat. Crazing may also result from paint
skinning as it begins to dry, and shrinking while the under-layers
or center remains liquid. Crazes may also occur from excessive
or sudden hot or cold temperatures.
Decoupage - A decorative
paperart technique using carefully cut figurative paper
illustrations. The cut pieces are then pasted onto nearly
any surface. Made popular in Victorian times, young women
would decoupage everything from floor screens to furniture,
and from boxes to album covers.
Defoamer – An additive
used to reduce foam in a paint or coating.
Dispersion - Process of
dispersing a dry powder into a liquid substance in such
a way that the individual particles of the powder become
evenly distributed throughout the entire liquid.
Drawdown - A layer of paint
‘drawn’ by use of a drawdown bar to evaluate
the characteristics of the paint.
Dry Brushing – The
technique of filling a brush with paint, removing virtually
all of it, and then brushing the nearly dry brush across
paper to alter and subdue color, or to enhance protrusions,
wrinkles and paper embossed areas.
Dye - A water or solvent soluble substance
made to color ink, paper, and textiles. Dye colors are less
stable over a long period than pigment colors, however after
application and protected properly, they have relatively
long life and allow a greater color variety. Dyes do not
scatter light, but absorb wavelengths and transmits others.
Embossing Powder - An acrylic
or resin-based fine-grained substance that will melt when
heat is applied to it. When cooled the powder leaves a raised
design.
Emulsifier - The process of dispersing
one liquid in another (the liquids being mutually insoluble
or sparingly soluble in each other). An emulsifier (also
known as an emulgent) is a substance which stabilizes an
emulsion, frequently a surfactant.
Emulsion - A mixture of two immiscible
(unblendable) substances.
Fade proof or Fade resistant - A color
that does not fade or resists change, when stored away from
a light source or a variety of other environmental factors.
Film - A thin continuous or unified coating.
Film Formation –
The result of an ongoing drying process, whereby a liquid
substance, usually a group of polymers, align into a stable
structure.
Finish – A term denoting the condition
of a paper surface. A high finish refers to a smooth, hard,
surface. A low finish refers to a relatively rough, toothy
surface.
Fish Eye - The crawling of wet paint into
a recognized pattern resembling small "dimples"
or "fish eyes".
Fixative – A substance, usually an
aerosol spray, that aids in preventing fading or smudging
of art materials such as chalks, pastels, and pencil.
Flow – The movement
of a coating during and after application and before the
film is formed.
Foxing – Brown spots of what appears
to be mildew in the paper’s surface, is actually fungus.
Penetrating the paper, they cannot be removed by erasing.
Occasionally it may be removed using bleaching techniques.
Frottage – In art, a surrealist and
"automatic" method of creative production developed
by Max Ernst. In frottage the artist takes a pencil or other
drawing tool and makes a "rubbing" over a textured
surface.
Gel - A somewhat elastic semisolid or gelatinous
substance composed of matter in a colloidal state that does
not dissolve.
Gesso - An opaque chalk-like base used
to prepare surfaces for painting, lettering, and gilding.
Glaze – A layer of paint, thinned
with a medium, so as to become somewhat transparent. A glaze
changes the color cast or texture (gloss or matte, for instance)
of the surface. Drying time depends on the amount of medium
used in the glaze; a higher ratio of medium to paint produces
a very thin, transparent glaze. Substances may be added
to professional glazes which increase the ‘open’
time. (USAQ offers a glazing product called Perfect Glazes.)
Gouache - Opaque watercolor
containing a colored pigment, binder, and an opaque filler.
(USAQ offers a gouache watercolor called MicaColor –
Pastelles)
Grain – The direction
in which most fibers in paper run, as a result of the papermaking
process. Paper tears more easily with the grain than against
the grain. For some paper varieties, folds made parallel
to the grain causing less damage, and creating smoother,
less bulky folds.
Grind - To reduce the pigment
particle size mechanically.
Grinding Slab - A flat
piece, usually of glass or stone, on which color is ground
from a coarse to a finely divided state, frequently with
the medium that is to blend it as a paint.
Gum Arabic – 1. A water-soluble gum
obtained from the acacia tree used in lithographic processes.
2. An acid-free powder or liquid binder used to make watercolors.
(USAQ offers this medium called Gum Arabic.)
Hot Pressed Paper - A smooth, glazed paper
surface produced by rolling and pressing a finished sheet
of paper through hot metal cylinders.
Hydrophilic – A substance which absorbs
or exhibits an affinity for water.
Hydrophobic – A substance
which does not absorb or exhibit affinity for water.
Ink – A fluid, semi-fluid, gel or
paste containing pigments or dyes, and is used in pens,
brushes, and pads for drawing, writing, stamping, and printing.
Inks for each of these purposes differ from one another
in their composition and physical properties.
Inorganic - Compounds that generally do not contain carbon.
Leaf – A very thin, fragile foil
or hammered precious metal, or metal-composite material,
which is applied by using a tacky adhesive or double-stick
tape, or sheets. It is sold in a range of types, colors,
sizes and styles. Also known as ‘gilding leaf’.
(USAQ offers this product in 6 colors called Gildenglitz.)
Leveling - The ability
of an applied wet substance to flow out to dry to a smooth
film without brush marks.
Lignin - One of the three main constituents
of wood, along with cellulose and hemi-cellulose.
Lignin acts as the cementing agent in wood, binding the
cellulose fibers together.
Lightfast - Referring to a material's ability
to withstand color change from light energy for a specified
amount of time. Colorants are described as lightfast for
a specified time exposed to a known amount of ultraviolet
light exposure. See ASTM Lightfastness Ratings.
Lightfastness – 1.
The relative degree of change or lack of change in color
of materials exposed to the same amount and character of
light. 2. A colored material that resists fading caused
by natural and artificial lighting.
Light stability - A material's ability
to resist change when exposed to light. Materials that are
not light stable can become brittle, discolored, and react
adversely with adjacent materials, such as adhering to each
other, becoming sticky, stretchy or pliable, bleed through
or stain the another item.
Medium - In paints, the continuous phase
in which the pigment is dispersed; synonymous with vehicle.
Mica – A transparent, flaky mineral
with excellent heat-resistance, characterized by the formation
of thin-layered sheets and ranges in color from colorless
to black, coppery, brown, gold and silver. When attached
to a pigment, it produces a wide range of iridescence, pearlescence
or metallic dry pigments. Dry pigments are extensively used
in many industries, such as paint making. Colored mica particles
and flakes are used as embellishments. Larger pieces called
block (USAQ calls Mica Tiles ©), are predominately
used for window, water and encapsulation techniques, and
may be shaped with scissors, or even die-cut. (USAQ offers
mica products called Mica Tiles, Mica Flakes, Mica D’Lights,
Mica Shapes, MicaCraft, and MicaColor Watercolors.)
Migration - The movement of chemicals (such
as acids, plastics, paint or inks) from one item to another.
Migration can occur without direct physical contact, such
as the migration of acids from one degrading paper to another
material or photograph.
Miscible - Relating to two or more substances,
such as water and alcohol that can be mixed together or
can dissolve into one another in any proportion without
separating.
Mixture - A heterogeneous
association of materials that cannot be represented by a
chemical formula and that does not undergo chemical change
as a result of interaction among the mixed materials.
Montage – A composite art piece made
by cutting or tearing photos then adhering them together
to produce a homogenous whole.
Open Time – The length
of time a coating (paint or adhesive) remains wet enough
to effectively work the brush.
Opaque – 1. An ability
of a coating to hide or cover, is known as opacity. 2. The
inability to allow any light to pass through a surface is
called opaque. Opaque is the opposite of transparent.
Organic - Designation of
any chemical compound containing carbon.
Paint – A substance
made of pigment and binder. Pigment provides color to paint,
and in its raw form it is ground. Paint may come in many
forms – dry powder, dry cake, liquid and paste.
Pantone - A color matching
system used in many industries to describe and reproduce
a specific color; first introduced in the early 1960's.
Permanence – The
resistance to any object or material to change with age
or exposure to deleterious conditions.
Permanent – A term
used to describe how long a media or substrate may potentially
last. A very vague descriptor unless there is testing data
to indicate what is meant by "permanent". Example:
Permanent Marker.
pH - The acidity (below
a neutral 7.0 pH ) or alkalinity (above a neutral 7.0 pH)
of a material. Acrylic paints must be alkaline in order
to maintain good working properties and shelf stability.
Acidic materials should not come in contact with natural
fibers such as cotton, because they speed up the degradation
of the fibers.
Pigment – A finely
ground, natural or synthetic, inorganic or organic, insoluble
dispersed particle which, when dispersed in a liquid vehicle
makes paint, and may provide, in addition to color, many
of the essential properties of paint including opacity,
hardness, durability and corrosion resistance.
Pigment Load - The amount
of pigment in paint, compared to the amount of binder and
other ingredients. Pigment Load may also refer to the maximum
amount of pigments or other solids that can be added to
a paint and still form a strong, stable film. Each pigment
varies greatly and therefore will have its own unique maximum
pigment load.
Pigment to Binder Ratio
- The ratio of pigment to binder solids in paint.
Pinholes - The film defect
characterized by small pore-like flaws in a coating which
extend entirely through the applied film and have the general
appearance of miniscule pinholes.
Polymer - The substance,
the molecules of which consist of one or more structural
units repeated any number of times.
Polymerization - The chemical
reaction in which two or more small molecules (monomers)
combine to form large molecules that contain repeating structural
units.
Repositionable Adhesive
- A pressure-sensitive adhesive with a low tack characteristic,
leaving a minimal residue, staining, or damage upon the
substrate when removed. (USAQ offers two repositionable
adhesives – dry Great Tape, and wet Duo)
Resist - A technique that preserves the
white area of cardstock.
Reversible Adhesive - An adhesive that
can be undone.
Resin – A general term applied to
a wide variety of transparent and fusible substances, which
may be natural or synthetic.
Retarder - A component
added to a substance to slow down a chemical or physical
change.
Rheology -T e flow characteristics
of a product; described as either ‘long and flowing’
or ‘short and stiff’.
Rheology Modifier - An
additive used generally for changing the viscosity or flow
of paints.
Setting Up - The conversion
of liquid paint during storage to a gel-like condition.
The process is usually reversible by agitation and thinning.
Shade - A mixture of a
color with black.
Solution - A homogeneous
mixture of two or more elements or compounds.
Solvent - A substance (usually
a liquid) capable of dissolving one or more other substances.
For example, the most common solvent is water. Paint remover
and alcohol are also just 2 of many solvents.
Surface Tension –
The property arising from molecular forces of the surface
film of all liquids.
Surfactant – An agent
or additive which reduces the surface tension, thereby improving
wetting and aiding in the dispersion pigments.
Syneresis - The spontaneous appearance
of a transparent liquid over an opaque liquid paint during
storage.
Tape – A material made of one of
numerous materials, such as cellophane, double-sided, dry,
mounting, foam, foil, plastic and masking tapes, all that
fastens two items together or may be used for creative techniques.
Thickener - Any material used to thicken
a liquid (increase viscosity).
Thixotropic – An
adjective describing a full-bodied material which undergoes
a reduction in viscosity when shaken or stirred, thereby
becoming the original full-bodied condition on standing.
Tint - A mixture of a color
with white.
Tinting Strength –
The measure of the effectiveness with which a quantity of
colorant alters the color of a material.
Tooth - A very slight surface texture,
caused by the pressure of the certain rollers during manufacturing
of paper. Tooth plays an important roll when using pastels
or chalk, as it ‘grabs’ and holds the particles.
Translucent - Between transparent and opaque;
translucent materials can be seen through, but not with
clarity.
UV light (ultraviolet light)
- Radiation present in sunlight, fluorescent light, and
to some degree incandescent light. UV light degrades the
components of paper, photographs, inks, paints, and adhesives.
Vehicle - The liquid portion
of paint, in which the pigment is dispersed, it is composed
of binder and thinner.
Viscosity - The physical
"thickness" of a product.
Viscous - Having relatively
great viscosity.
Wash - A layer of color, often uniform
in tone, applied across the paper with a brush or sponge.
Watercolor – A paint in which water
is used as the vehicle for carrying the pigment from the
brush to the paper. Cardmakers can enjoy a huge variety
of types and hundreds of colors. Watercolor in tubes may
be mixed with those on a palette or in a pan, and in conjunction
with watercolor markers. Watercolors may be mixed with gouache
and provide a base of color for pastels, pencils and markers.
Mica-based watercolor paints provide a sparkling feature
and vary greatly from translucency and opacity. Gum Arabic,
derived from acacia trees, acts as the binder and is resoluble
even after drying. Good watercolors contain emulsifiers
that aid in rewetting and viscosity, and aid in providing
smooth color transitions.
Forms: Liquid –
A watercolor solution able to be poured or brushed without
requiring the addition of water. Often, liquid watercolors
contain dyes which are not lightfast.
Pan Paint
– A watercolor paint, poured and hardened in a palette,
which may be re-wet to be used. (USAQ offers pan paint watercolor
palettes, because mica settles and does not lend itself
to tubing.)
Tube Paint –
A tubed, viscous watercolor to be applied to a palette,
and further wetted-out to be used.
Waterproof / resistant
- A materials ability to resist change when in direct contact
with water. This includes, but not limited to, softening,
migration, swelling, bleeding, or dissolving.
Water-soluble - A material that dissolves in water.
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