The best general purpose cleaner is a liquid detergent. It’s better to use too little than too much. Liquid is recommended over powder because some powders do not completely dissolve and the granules will lodge in the toweling. Never experienced this. And its only beyond a point of solubility that the powders wont dissolve, a.k.a. too much added in the wash.
Wash in cold water only. Warm water can be tolerated, but hot water cannot. Polyester and polyamide both shrink in hot water. If you wash in hot water the fibers will shrink and the towel will not perform as intended.
Agree with DF. Cotton on the other hand shrinks considerably. Im thinking articles of clothing though, but there are near similarities) But I have never experienced a poly/poly blend shrink.
Do not use fabric softeners of any kind. The softener will become lodged in the microfiber reducing its ability to absorb water, clean and pick up dirt. In short, you’ll have a soft towel that’s useless.
I agree with this, fabric softeners are water repellents also......
Do not dry above medium heat. Treat microfiber towels the same as you would your delicate clothing. Drying with high heat is worse that washing in hot water.
I dry on hi heat, but thats my dryer. On a side note to Leo's reply, if you have an electric dryer, the element shield can reach temperatures consistent with melting synthetic products. This is a firsthand experience....