GRAINING AND MARBLING – Part 1

Mediums: Both oil and water colour mediums are used in Graining and Marbling, each has its own advantages and limitations.

Water Colour Mediums

Advantages:

1.    Dries quickly therefor it does not collect dust giving a cleaner finish.
2.    The coating is extremity thin and for this reason gives surface flatness and smoothness.
3.    Colours do not darken though oxidation.
4.    Colours are extremely transparent.
5.    Speed of completion of work – can be grained or marbled then varnished within one hour.

Disadvantages:

1.    The medium dried too quickly to be used on large areas.
2.    It is not easy to maintain evenness of colour at the ends of moulded panels.
3.    Medium and dark tones require two coats of varnish.
4.    Tends to be a little gritty.

Oil Colour Mediums

Advantage:

1.    Dries slowly, allows ample time for manipulation of pattern. Can be modified to suite weather condition.
2.    Suitable for large areas.
3.    It offers the best medium for combine and figuring (eg. Oak).
4.    Gives more depth (especially over water colour)

Disadvantage:

Slow drying – needs overnight to harden – 2-3 days process.

Preparation of Oil Colour Mediums

Contents:  Turps, Linseed Oil, Varnish (flat) in equal quantities, Driers (if required), Colours – Oil strainers

Note: Variation of these quantities may be altered to suit individual circumstances. Eg The addition of scumbling medium to graining colour to obtain ‘hold up’ of markings, or the addition of linseed oil to allow longer working time

Preparation of Water Colour Mediums

Contents: Pigments – water – binder

Binder or Fixative (vinegar; stale beer; skimmed milk; thinned P.V.A. resin)

Using a palette knife, grind the pigment with a little water on a glass palette, and then add the pigment to the remainder of the ingredients.

Note:

1.    If beer or vinegar used as a binder, thin with 3 parts of water.
2.    If skimmed milk is used, thin with equal parts of water.
3.    P.V.A. resin should be used sparingly.

A few drops of glycerine may be used as a retarder in hot weather – or washing up liquid may be used.

If crayons are required for graining and marbling:

Content type is suitable for oil work

Crayon pencils for water work (check that they are compatible with the varnish before using).

Graining and Marbling Tools and Brushes

Mottler: Pure white bristle filling, set in a metal ferrule. Sometimes has a short wooden handle.
Size: 50mm and 75mm wide.

Use:

1.    For simulating the soft lights and darks seen beneath the surface grain of many woods (mottling).
2.    As a general graining brush to simulate the straight grain and heartwood patterns of mahogany, walnut and similar woods.

Over grainer: Pure white bristle filling, set in a metal ferrule. Similar to a mottler but with a longer filling and much thinner in section

Use: To add fine parallel grain patterns to complete (over graining). Often used with water graining colour and passed through a course comb to separate the filling.

Pencil Over grainer: Separate tufts of pure white bristle filling, set in a metal ferrule. Also available with a pure sable hair filling but expensive to buy

Size: 50mm and 75mm wide.

Use: Similar to those for the over grainer.

Fan Fitch Over grainer: Separate tufts of pure white bristle filling set in a flattened metal ferrule to produce a fan shape.

Size:25mm and 38mm at the widest end.

Use:

1.    To simulate the curly grain patterns of burr walnut, pollard oak and similar decorative woods.
2.    Used as an over grainer.

Flogger: Long pure bristle filling set in a wooden stock or a metal ferrule

Size: From 75mm to 100mm wide

Use:

1.    To simulate the pore of wood by beating wet graining colour.
2.    To imitate the decorative texture ‘dragging’.

Badger Softener: Separate tufts of pure badger hair filling, set in a wooden stock. Some smaller varieties are set in a metal ferrule.

Size: 75mm and 100 mm wide. Smaller flat varieties: 23mm, 38mm, 50mm and 75mm wide. Smaller round varieties: small
size No 2, to large No 12.

Use: to gently fade-out or soften the sharp edges of patterns produced in graining and marbling. Although intended only for use with water based materials, they are often used with oil graining colour and marbling glazes.

The list of tools to do Graining going on and on, ask us for more details on 1800 204 145.