Your minimum of 65°F refers to an entirely different kind of dye, Eric. You're talking about a minimum temperature for Procion MX dyes. I personally would set the minimum temperature for Procion MX dyes, especially the turquoise, at 70°F (which is 21°C) or even higher, but some people find somewhat lower temperatures to be adequate. The True Tie Dye video says that the minimum temperature for Procion MX dyes is only 60°! It works for them. My experience is that you get brighter colors if you make sure your dye reaction has plenty of warmth; I would never (again) try to dye with Procion MX dyes at below 70°F, because I don't want to waste any of the dye unnecessarily.
Andy is using an entirely different kind of dye, which is known as
Remazol dye. (He mentioned this elsewhere, there was no way for you to know in this thread.) It is chemically rather different from Procion MX dye, though both are
fiber reactive dyes and form a strong covalent chemical bond with the fiber. Remazol dyes (which he bought as Createx Colors, back before they were discontinued) do not react nearly as easily as Procion MX dyes, because they contain a "masking group" that prevents them from reacting directly with the water, as Procion MX does.
They need a lot more warmth. This makes them extremely convenient to use! Instead of having to mix up the dye fresh from powder every few weeks, with Remazol dyes you can, depending on your supplier, just buy a bottle of liquid, the dye already dissolved. It's so simple and easy to measure out a spoonful of liquid dye and have it dissolve instantly. You don't have to wear a dust mask or clear the entire room and cover every food-preparation surface in the entire room, as you do when measuring out powdered dyes! Instead, you only have to protect the surface you're actually working on. You can leave the fruit in the bowl on the other side of the kitchen. This is no big deal to those who are equipped with a proper dye studio, but it represents a great advance in convenience for those who work in their kitchens.
The ideal temperature range for Remazol dyes is between 104°F and 140°F. (This equals 40°C to 60°C.) You can easily reach this range with hot tap water, so there is no need to cook the dye (as there is with
all-purpose dyes such as Rit dye). In contrast, the ideal reaction temperature for Procion MX dyes is 30°C, which equals 86°F.
You certainly can use Procion MX dyes below their optimal temperature of 86°F, but making sure that your temperature is not
too far below this helps to avoid the curse of pale colors, especially pale turquoise (the latter is always a dead give-away that someone's dye studio is too cold). Basically, what you're doing is substituting extra time for extra warmth, because a colder chemical reaction always proceeds more slowly. You cannot keep lowering the temperature and extending the reaction time indefinitely, though, because it quits working below a certain temperature, 60°F or 65°F or 70°F, depending on who you ask.
You can also use Remazol dyes below their ideal temperature of 104°F, but at some point below that temperature, your results will no longer be as intense in color. At what point? How low can you go and still get optimal color intensity? I'm not sure, but I'm pretty sure that 65°F won't work! Remazol dyes definitely need higher temperatures than Procion MX dyes, in order to meet their full potential. If your Remazol colors are dimmer than you like, the thing to try is adding warmth. There are many ways to add warmth without paying for the energy to heat your entire studio, such as by putting your freshly dyed wet items in plastic bags on top of a waterproof electric heated mattress pad, or by putting them in small buckets and placing them in a large sinkful of very hot tap water. (Heating your entire studio to a high enough temperature in the winter works well only if it is small.) The garbage bag trick is an excellent one, because the black plastic bags can absorb a lot of heat from the sun, as long as they are placed on a surface other than the cold ground, such as a table or a stack of cardboard. It's not all that great as a substitute for steaming, when
acid dyes require that, but it's a fine way to reach the more moderate temperature preferences of Remazol dye.
(The most economical source for Remazol dyes these days in the US is from PRO Chemical & Dye. See "
About Vinyl Sulfone Fiber Reactive Dyes" for more info on Remazol dyes, and international sources for them.)
Paula
