Adjustable temperature: 240 oF~410oF (120oC - 200oC) for all hair types. For normal hair, temperature setting at 370-390oF is recommended; for bleached, fragile, damaged and fine hair, the lower setting is advised; for coarse, thick, ethnic and resistant hair in healthy condition, maximum heat on high setting is used to save time and effort.
Sedu gets most things right. Fine, damaged hair should use a lower setting and healthier hair can take more heat. It's the use of the word "ethnic" that may confuse some people. These instructions are not unique to Sedu. Most flat irons have a similar guide. I'm just picking on Sedu today.
We know that ethnic hair is not necessarily coarse hair. We also know that heat softens the keratin of hair. But there are some people who don't know. Some people may read these instructions thinking that heat setting should be dictated by ethnicity.
Even with very coarse hair, the highest heat setting can still damage or "train" hair. This is how straighter ends/ pieces can come about. The lowest possible setting, to get the desired results, should always be used.
Here are some tips for getting a sleek look without high direct heat:
-Your hair should be well-conditioned and detangled before you begin the straightening process.
-Blow dry or roller set first. I use the tension blow dry method on cold.
-Flat iron in smaller sections
-Pull the hair taut with your hand as you are straightening
-Do the final pass of the flat iron with a comb (comb chase method to ensure even distribution of heat)
-If you still don't have the desired straightness, try wrapping your hair with Saran wrap or a head tie and sitting under a dryer for 10-15 mins.