The appearance of small brown spots on freshly painted wood trim and doors is a common issue known as “tannin bleed.” Tannins are natural compounds present in certain types of wood, such as pine, cedar, and redwood, that can bleed through the paint when exposed to moisture from the paint or environment. This phenomenon typically occurs when painting over unfinished or unprimed wood, allowing the tannins to seep through the paint and manifest as those unsightly brown spots.

To address and prevent tannin bleed, the following steps can be taken:

1. **Preparation:** Properly prepare the wood surfaces before painting by cleaning and/or sanding them to create a smooth and clean surface. This helps to remove any existing stains, sealers, or contaminants that may contribute to tannin bleed.

2. **Priming:** Apply a high-quality stain-blocking primer specifically designed to prevent tannin bleed. These primers create a barrier that inhibits the tannins from penetrating through the paint layer. Be sure to follow the manufacturer’s instructions for the proper application of the primer.

3. **Paint Selection:** Opt for a high-quality paint with good coverage and stain-blocking properties. Paints labeled as “stain-blocking” or “high-hiding” are formulated to prevent tannin bleed and ensure a uniform finish.

4. **Multiple Coats:** Apply multiple thin coats of paint rather than one thick coat. This helps to build up a sufficient barrier against tannin bleed and ensures a more consistent finish.

5. **Touch-ups:** If you notice brown spots appearing as the paint dries, allow the paint to fully cure and then spot-prime these areas with a stain-blocking primer before applying additional coats of paint.