The packaging: thick cylinder to hold, however it's light enough to be maneuverable. Caps stay on tight and won't fall off easily with travel.
The formula: Matte finish, wet on application, once dried down stays all day. Comparing this with 2 other eyeliner stamp brands I've tried, this formula outlasts them.
The stamp: this is what led to 4 stars and not 5, I'm not a fan of the curve. I got grande, and the length of the wing is good, the curve just makes it hard to mirror the angle on both eyes. This leave one wing in line with my eye shape, and the other flicked up like 1950s style. If it was straight, it would make it easier to judge where the wing ends up at in terms of angle to mirror on both eyes.
To summarise, wet application, dried matte, lasts all day and takes practice to mirror the wings on either eye. Image attached is 9 hours of wear, on a rainy day.