Operations in papermaking:

• Beating is the mechanical treatment of pulp fibres to increase fibrillation and bonding strength.
• Sizing: Rosin, soap, wax emulsion, and alum (aluminium sulphate) are chemical additives used during internal sizing of paper to reduce water absorbency and prevent ink feathering.
• Loading is the addition of inorganic fillers (clay, talc, calcium carbonate) to improve opacity and smoothness.
• Colouring involves dyes and pigments added to give paper a specific shade.
  
  Option breakdown:
• Mechanical fiber refining.
• Sizing is the process of adding rosin and alum to impart water resistance.
• Loading uses mineral fillers.
• Colouring uses dyes.