A-level Applied Science/Colour Chemistry
About this Unit
From the AQA Specification:
You will need to produce a portfolio of evidence detailing the extraction and application of a natural (plant) dye and the preparation and application of a synthetic dye. You should also include evidence detailing the use of organic pigments in an oil-based paint.
Comment: Although most natural dyes are plant dyes, some are derived from animals or minerals. This is of little consequence to the work, however.
The pigments in oil-based paints are usually inorganic. I have assumed that inorganic pigments for paints are valid. AQA do not give any organic pigments as examples; they suggest hydrated iron (III) oxide, zinc potassium chromate (VI), chromium (III) oxide or iron (III) hexacyanoferrate (II) (Prussian Blue).
How you will be assessed
This unit is assessed through the work you complete for your portfolio.
The marking criteria are found in the AQA specification.
What you need to know