Dirt and water damage on a watercolour painting can be removed, restoring the artwork to its previous state. Colour fading can not be reversed; it can only be prevented, or stopped from fading further. Each type of damage has its own set of procedures when restoring the original artwork to its former glory. Cleaning dirt and debris from a water colour painting is the simplest of them all.
Remove the painting from the frame. Separate the watercolour from the glass frame immediately after it has become saturated. Leaving the image in place pressed against the glass results in the image being bonded permanently to the glass. Mold also begins to form after saturation.
Lay the watercolour on a flat, dry surface. Lay the artwork on a towel, blanket or on dry grass in the yard. Leave the artwork untouched until completely dry.
Mist the front and back of the watercolour with a light coating of spray Lysol. Do not substitute with a chemical that contains bleach. The damage incurred from the bleach is irreversible. Wait for the mould to dry out and become dormant. The mould will become powdery.
Brush the mould off of the watercolour lightly with a clean, dry, soft-bristled paint brush.
Insert the painting into the frame.
Break a loaf of bread in half. Grab a handful of the white inner portion of the bread. Roll the dough into a ball.
Scrub the dough gently against the watercolour painting.
Replace the dough as the piece you are working with gets dirty.
Brush the breadcrumbs off of the watercolour using a clean, dry, soft-bristled paint brush. Make sure that all breadcrumbs have been removed from the painting.
Replace the glass in the frame with a UV3 coated Plexiglas. This will reflect the UV rays that cause the colour to fade.
Move any watercolour artworks away from direct sunlight. Artwork with the UV3 Plexiglas will not prevent all UV rays from damaging the colour in the painting. Direct sunlight can harm the colour, or even raise the temperature of the painting altogether.
Avoid hanging watercolour paintings where the temperature of the artwork would rise above 21.1 degrees Celsius. Avoid hanging on outside walls that are not properly insulated, over fireplaces or near furnace grates.
Replace all florescent lighting with incandescent light bulbs. Do not use direct lighting of any type on a watercolour.