A feather and a sponge can be your best friends in creating specialty
paint effects. A good, stiff turkey feather is ideal, although in
a real pinch, you can steal a few from a feather duster. Purchase
a sea sponge from a paint, hardware or bed-and-bath store (they're
not cheap, but they are reuseable: make sure you rinse your sponge
out well when you're done, and you'll be able to use it over and over).
Choose a large sponge that has a lot of rough edges and texturing
This effect works nicely on architectural elements - we've used it
on platforms, recessed bars, countertops, step risers, and a tub surround
(for the play Bathroom Humor).
Decide what colors you want your marble to include. Three is the
minimum for the best effect - a dark, a medium, and a light - but
you can use more if you like. (One of my favorite combinations for
green marble is jade green for the medium, dark green and flat black
for the dark, and a very light sea-green for the light.) Find a piece
of real marble, or gather some color photos to study the play of colors
Gather the following materials: coffee cans or margarine containers
for mixing (one for each color plus an extra), roller or brush for
applying a base coat, a bucket of water, feather, sponge, rubber gloves,
and your marble sample.
Using a brush or roller, lay a base coat of the medium color on the
object you want to marbleize. Pour out a little of your dark, medium
and light colors into separate containers and add a little water to
each. Now's a good time to pull on your gloves.
Wet your sponge first in the bucket of water (and keep rinsing it
out periodically as you work to keep it damp), then using the dark
paint, begin daubing it on over the base coat (this works best if
your base coat is still a little wet, although that's not necessary).
Rotate your sponge and vary both the amount of paint on the sponge
and the pressure as you apply it to avoid a repetitive pattern. Vary
the colors by dipping your sponge in the medium and or light colors,
then back into the dark, and vice versa, to create a mottled pattern
- don't worry about keeping the colors in your containers pure; the
random mixing is OK. And feel free to go back over areas that you've
already painted - this adds depth. You may want to occasionally press
down harder and lay down a swath of color using a scrawling motion
that mimics the pattern of real marble (keep your marble model or
photo close at hand to study as you go).
When you're satified with the mottling, it's time to do the veining.
Pour out a fresh batch of the light color into a small container (you
won't need much) and add enough water so that it's smooth and spreadable
but not drippy. Dip your feather in the light color, then pull it
across the lip of the container to remove any excess. Study the mottled
surface of the object you're marbling to decide which direction the
veining would logically go (you might want to follow some of those
scrawling swaths that you created), and then lightly draw the tip
of the feather in a wavy line across it, twirling it just a bit as
you go to vary the width of the line, and tapering it off lightly
at the end. Continue like this, varying the length, width and direction
of your lines, and making appropriate forks and splits in the veining
(again, keep your marble sample handy for reference). Vary the color
of the veining by occasionally dipping the feather into the medium
or dark and then into the light. Know when to stop - too much veining
will look unnatural.
Finish off the marbling effect by VERY lightly sponging on some of
the light, dark and medium paints in random spots, barely touching
the sponge to the surface, again rotating your sponge to vary the
pattern (spattering, by hitting a wet brush to produce fine paint
droplets also works, although you may not have as much control as
you do with the sponge). Make sure some of these light touches are
applied over the veining so it doesn't jump out from the rest.
EXTRA TIP: If your marbled piece is in a spot on the stage
where glare from the lights is not going to be a problem, you can
give it a shiny glaze by applying a mixture of white glue (Elmer's)
and water when it's dry - mix in water until the glue has a runny
enough consistency to spread easily with a brush. This technique works
for any painted surface that you want to have a shine to it - it's
especially good for floors, as it adds a light protective coat.
The books Recipes For Surfaces, Volumes I and II by
Mindy Drucker and Nancy Rosen, contain excellent step-by-step instructions
for a lot of different natural paint effects, as well as a lot of
photos of the real thing to give you something to go by.