These are the preferred range of Dyes and they are mostly suitable for Pure Wool. The dyes in the different shades are primary grouped considering their exhaustion behavior, colourfastness and new characteristics on wool.  And they are as per below mentioned groups :

Leveling Dyes :-

These type of Dyes are required acid dyebaths using Sulphuric / Formic Acid. The pH of the dyebath is around 2.5 to 3.0. Usually the dyes are bright with good leveling properties and passes moderate wet fastness.

TPM Dyes :-

These dyes are dyed in weak acid / neutral bath employing a pH of  4 to 4.5. Acetic Acid or Acid liberating salt such as Ammonium sulphate or Acetate are used commonly. The shades obtained are bright with excellent Colourfastness properties.

1:1 Metal Complex Dyes :-

Above group comprise pre-metallized 1:1 Metal Complex Dyes. You can get brilliant level properties and good colorfastness. Due to outstanding leveling properties, these are most suited for the production of even at light shade with good colorfastness.

1:2 Metal Complex Dyes :-

The above said dyes are dyed in a neutral or slightly acidic bath using pH at 5.5 to 7. And they have excellent degree of infiltration, hence most suited for woven goods. And also shades obtain good fastness properties.