Procurement compares coatings by price per litre because that is what appears on a quotation. Coatings deliver protection by dry film thickness over area, and the bridge between the two is volume solids. Ignoring it produces buying decisions that are precisely backwards.
The comparison, worked
Primer A: 180 AED per litre, 75 percent volume solids. Primer B: 140 AED per litre, 50 percent volume solids. Specification calls for 100 microns dry film thickness.
Coverage equals volume solids times ten divided by DFT. Primer A gives 7.5 square metres per litre. Primer B gives 5.0.
Cost per square metre at theoretical coverage: Primer A is 180 divided by 7.5, which is 24 AED. Primer B is 140 divided by 5.0, which is 28 AED. The cheaper drum is 17 percent more expensive per square metre protected, before any other factor is considered.
The secondary effects
Lower volume solids means more coats to reach the same film build on many products, and each coat carries labour, access time and recoat waiting. It also means more solvent evaporating, which raises VOC and, in enclosed spaces, extends ventilation requirements. Higher solids products often reach specified thickness in fewer passes, and on a structure requiring scaffolding, saving a coat saves far more than the material difference.
Where low solids products still make sense
They are not inherently inferior. Lower solids formulations can offer easier application, better penetration into porous or rusted substrates, and lower viscosity for brush work in confined areas. Surface tolerant primers deliberately trade solids for wetting ability. The point is not that higher solids always wins, but that the comparison must be made on cost per square metre at specified thickness, not per litre.
Building it into procurement
Ask for volume solids on every quotation and compute cost per square metre before comparing. Apply the practical loss factors from our coverage calculation guide consistently across all options so the comparison is fair. Then consider coats required, access cost and programme.
MENA Industrial Supplies quotes coatings with volume solids and coverage stated, and will run the cost per square metre comparison with you on request.