Creating a realistic watercolor painting requires variety in your mark depending on the objects in the painting. Painting realistic looking fabric can prove very difficult for beginners because fabrics have folds, twists and weaves that seem complicated. Fabrics need to have a noticeably different texture than the smooth objects in the painting. A glass bottle, for example, has a completely different texture than a twisted tablecloth. Create these fabric textures by using different brush strokes or unconventional painting tools, such as paper towels and salts, to leave behind impressions and prints.
Set up your painting reference where you can easily see it from your work area. Make sure you can easily see the fabric texture in your still life or photograph.
Fasten140-pound or heavier paper to a flat surface with masking tape to prevent the paper from moving.
Lightly sketch the fabric and any other objects in the still life or picture reference on the paper with an HB pencil.
Apply masking fluid with a sable brush to any highlights and fine lines in the fabric, such as highlights in twists or stitching marks, to protect these areas.
Mix your first color to match the general color of the fabric. Do not worry about the lights and darks yet; for now, just focus on one general base color of the fabric. For example, a green cloth may have areas of yellow and blue, so you should mix a middle green tone.
Thin the mixed color with water and apply a light wash over the area where the fabric is sketched using a large brush. Gradually build up darker washes that vary in color with medium-sized brushes to create shadows.
Imply texture by breaking apart your brush strokes, similar to an impressionist painting. Use a dry brush, which is a brush with very little water, to leave scratchy strokes that look like the weave of fabric or use a very wet brush full of water to pool the paint and create interesting fold and bleed lines.
Drop some table salt onto wet watercolor paint after applying it to the paper to make a grainy fabric look. Apply plastic wrap to wet paint on the paper to leave dark pools and light lines that will look like drapery or crumple a paper towel and dab the wet paint to leave behind fabric looking lines.
Remove the masking fluid with a white eraser. Use a small brush to draw in dark lines and shadows in folds or weaves to create emphasis on the textures you created.
Experiment with different types and textures of watercolor paint to create different textures in your painting. Cold pressed paper will have a very strong texture, while hot pressed paper will leave your painting smooth and uninterrupted.
Use anything that has a texture to create texture in your painting. Try pressing heavily textured canvas or fabric scraps against your wet paints to leave an imprint of the weave on the paper.