kcgdz/ink-calculator ? reverse-engineered prompt

Build me a simple Streamlit app for estimating ink consumption for printing jobs.

I want it to help people in security printing and specialty inks quickly calculate how much ink they need using area, coverage, ink density, and a substrate factor. It should include a bunch of common print methods like offset, UV flexo, gravure, screen, digital, and security inks, plus the UV flexo variants and substrate options like coated paper, uncoated paper, cardboard, plastic, metallized, and security paper.

Please also add a Pantone mixing section that helps estimate CMYK plus orange, green, violet, and special color costs. Make the interface easy to use, with clear labels, helpful defaults, and outputs that show the result in a practical way. If it makes sense, let users export the results as CSV or JSON.

Use the data and formula from the README, and if you need to check anything current, look up the docs online.