How should excess glaze on the bottom of a ceramic piece be removed? aWashing with water bWith a damp cloth/sponge cBlowing air dWith a scraping tool

The excess glaze on the bottom of a ceramic piece should be removed with a scraping tool. Here are the steps:

1. First, make sure the ceramic piece is completely dry. Trying to remove glaze from a wet piece can cause damage.

2. Use a ceramic scraping tool, which can be found at most craft stores or online. These tools are specifically designed for working with ceramics and will not damage the piece.

3. Gently scrape the excess glaze off the bottom of the piece. Be careful not to apply too much pressure, as this can scratch or chip the ceramic.

4. Once the excess glaze has been removed, you can smooth out any rough edges with a piece of fine-grit sandpaper.

5. Finally, wipe the bottom of the piece with a damp cloth to remove any dust or debris.

Remember, it's important to always wear safety glasses when scraping or sanding ceramics to protect your eyes from dust and debris.