Creating a faux marble finish with sponging is an affordable way to bring a level of design sophistication into your home without the expense of installing real marble. If this technique is applied carefully you will be amazed at the impressive results.
Step 1 - Prepare the Surface
This technique works best with oil-based applications. To ensure a more realistic result find a small piece of real marble to provide an example of the look you desire. It is better to apply this effect to areas that could have been made from real marble. Examples include, mantles, lamps, flooring, columns, etc.
In these instructions we will be referring to an accent wall. If your current wall is covered with latex paint (water-based), you will need to lightly sand the surface with the sandpaper. This will remove any previous gloss on the wall and will allow the new coat of paint to adhere.
Step 2 - Apply Base Coat
Cover the accent wall with the base coat. This will need to dry completely before applying the next step. Drying takes approximately 12 to 24 hours.
Step 3 - Apply First Glaze
Add to the glaze of oil varnish and white spirits some artist's Burnt Sienna. This is not an opaque mix. You want to create a thin wash-type effect. Apply this mix on the wall in patches, overlapping in some areas and moving in a diagonal pattern across the wall.
Step 4 - Apply Second Glaze
Mix your oil gray into a fresh batch to the glaze mix. This must also be a transparent mix that will then be applied to the wall. Fill in gaps and overlap on some of the first coat of the sienna glaze. Blend the 2 colors with the soft brush.
Step 5 - Dab with Rag or Newspaper
Using a lightly wadded up rag or newspaper you will now dab across the surface of the wall, lightly and in random places.
Step 6 - Dab with Sea Sponge
Dip the sea sponge into some unmixed white spirit and dab the wall in random places in the same way you dabbed with the newspaper or rag. This will cause the glaze on the wall to spread, so make sure the sponge is damp and NOT dripping with the spirit. Once again soften the effect with your brush.
Step 7 - Feather Pulling
Dip the feather into the white spirits and drag it across the wall in a diagonal direction in some areas and at random lengths. Vary the application by using the broad side of the feather as well as the tip. Soften some of these strokes with the brush.
Dip another clean feather in the pure paint of burnt sienna or another dark color of your choice, then work another layer of feather veining. Move in the opposite diagonal direction of the first feather veining. Soften some of these lines with your brush.
Step 8 - Spatter
Using the toothbrush, spatter some white spirit or color onto the wall. Do this in a random way and sparingly.
Step 9 - Evaluate
Step back and view the wall, if there are some spots that need more color. Use your sponge mixed in the glaze/color mix and dab more onto those areas.
Step 10 - Finish
Finish the wall with 2 coats of oil-based varnish.
The most difficult aspect of this technique is the feather veining. Try using your other hand for this. Also, do not feel limited to the color examples, choose any realistic marble colors added to the same base mix of glaze and white spirits.
This is a labor intensive process which does not have to be completed in 1 day. Also, oil-based paints are more toxic than latex, so you may need to use a mask during applications.