The seed coat of many seeds has evolved to withstand years of drought, traveling across bodies of water, periods of harsh weather, or even exposure. These seeds may be difficult to germinate if sowed without pretreatment. For seeds with thick impermeable coats, it is often best to use scarification methods. Seeds with lighter coats may need only be presoaked. Some seeds require a cold season before they will germinate; these will benefit from stratification.

modifying the surface tension of a substrate to improve ink adhesion. Common pretreatment methods include: chemical, flame, corona or plasma.