One of my favourite products for travelling is YSL Touche Brilliance Sparkling Touche for lips. There is another Touche Brilliance pen that is a foundation highlighter. Sometimes it's not just the product but rather the packaging that makes sense. This lip pen doesn't spill or leak out and mess up your makeup bag. Especially good for air travel because of cabin pressure when the plane is in flight.
To use, remove the cap and press the pump at the end of the lip pen to release the liquid then brush it on the lips. I usually press it a couple of times to get enough colour on my lips. The liquid inside is a happy combination of lipstick and lipgloss. It is highly pigmented like lipstick but liquid like lipgloss. Nice and fruity fragrance with a lovely shimmer on all the colours too.
This lip pen contains 2.5ml or 0.08oz similar to a tube of lipstick, S$38.