2 oz Ludigol
Really, we don't recommend Ludigol anymore. Don't buy it. In our tests Ludigol does not make a difference in your tie dye project.
Only buy Ludigol if you've tested it for whatever you do and you know it makes some sort of difference. We don't think it does.
Ludigol is used in tie dyeing or other direct application dyeing. It is generally not used in solid color dyeing. Reactive type dyes slowly break down once they’re mixed with water, and over time the dye becomes less effective. Soon the dye solution will lose all effectiveness. Ludigol is added to the dye to keep the dye from breaking down in the water at higher. Ludigol keeps the dye fresher longer, and allows more dye to react with the fabric, helping the colors to come out brighter. We estimate that two ounces of ludigol will prepare enough chemical water to tie-dye about 60 t-shirts.