Essential oils are categorised into 3 ‘note’ categories: top, middle and base, with some crossing over into separate categories. Top notes are the lighter fragrances and usually the first ones you smell in a blend. Citrus scents are a popular choice for customised soap recipes and their light and fresh scent is a good example of a top note. This type of scent will also generally disappear quickly. If you want a heavier fragrance, middle notes offer a good balance and tend to be spicy, woody or occasionally citrusy. Some examples of middle notes include lavender, rosemary and lemongrass, with this type of scent usually lingering longer than a top note. Base notes are heavier and are usually spicy or earthy, with some floral options like ylang ylang also falling into this category. A base note will last the longest and when mixed with a light note can create a nice balance for a personalised soap.