Packaging - The bottle is a fairly simple and practical shape, I quite like the chunky handle as it gives you a better grip when applying the polish. As I've purchased darker shades, and the bottle is labelled in black ink, I can't actually read it, but I'm not particularly fussed about that.
Consistency - As a fan of glitter nail polishes, I notice that they can sometimes be very gloopy and clumpy, but these ones are actually pretty smooth. Not too runny however, which you would expect from a cheaper polish.
Application - With the purple one, I applied a different purple nail polish first, because this polish is clear with glitter. The glitter applies pretty evenly, and you don't need about 10 coats to get good coverage! As for the black one, one coat was perfect! Totally opaque, not watery or at all streaky. Drying time for both was about a minute per coat.
As you can see, I'm not very good at applying nail polish haha! However, I'm thoroughly impressed by this collection and will most definitely be purchasing a few more shades to add to my ever growing nail polish collection(well into my 70-odds now). Such great value for money and the quality is amazing, highly recommended by me!
So, Boots SinfulColors Nail Polish collection gets a well deserved 5/5 cosmic hearts!