In the past woodwork (trim) was once painted using oil based paints. As times & legislations have changed so have the paints available. Oil based paints although more shiny are prone to going yellow over time. The oil content is what causes the yellowing in low natural light. Water based paints for trim will not yellow; they stay white as there is no oil in them. We recommend water based paints as it is quicker drying, none yellowing, environmentally friendly, low odour as well. There are different types of finishes for different budget.