Mascara base, or primer, helps produce more voluminous lashes and prevent smudging.
Orbis Styling Mascara Base (HK$149)
Does what it's supposed to - bulks up lashes and helps to limit smudging - but for the price, you may as well apply more mascara.
Majolica Majorca Lash Bone Black Fibre (HK$115)
The primer does its job in lengthening short eyelashes, but you need to put up with the feeling of a gluey layer underneath your already thick mascara. Not recommended for sensitive skin, as it makes removal an even lengthier process.
Clinique Lash Building Primer (HK$100)
This white primer lengthens surprisingly well, but doesn't have much effect on volume. Not too thick or sticky, this goes on well but makes lashes feel weighed down.
Shu Uemura Lash Builder (HK$195)
This lash-boosting serum claims that it grows your lashes stronger and fuller, and prevents loss. Lashes certainly feel stronger, but it will take a few weeks before any length-increasing effects are noticeable.
MAC Prep + Prime Lash (HK$125)
Visibly adds bulk to skinny lashes, meaning you need only one coat of mascara. Seems to make removal easier, too, but not sure the price tag is worth it.