Was thinking earlier, that categorising the materials in your material inventory, the same way that the material traders have the, would make material gathering much easier i.e. you could see what materials you could gather to trade for higher lower grades. Displaying it like this would be perfect:
Category 1
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
Category 2
Grade 1...etc
Category 1
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
Category 2
Grade 1...etc