This primer is essential in my beauty routine, I use it on a daily basis.
I would like to thank the ladies on the MU-board for suggesting this product!
I have oily lids and have always had to touch up eye makeup during the day or wipe it off as it would look terrible a few hours into the day (or night). Not anymore! This primer goes on silky-smooth and dries down to a satiny base; a perfect canvas for any type of eye product.
I use TFSI on its own to create even skintone on lids, under powder eyeshadow to stop creasing, under loose eyeshadow to prevent fallout, under cream shadows to keep them from melting/sliding off, and in preparation for eyeliner to make it stay and not transfer onto upper lids. This product will also ensure your mascara doesn't smudge onto eyelids and your brow highlighter from migrating out of place.
The product is easy to apply and shadows are easy to blend/layered, liners go on without smudging or dragging. Lasting power is excellent; approximately 10-12 hours.
I would suggest you shake the tube to make sure contents are well blended, also in my experience the product goes on more even when slightly warmed up (just holding the tube in your hand for 30 seconds will do the trick).
Compared to UDPP it has the obvious advantage of a clever packaging and a formula that doesn't cause irritation, rash or crepey lids. It is also much more emollient and ensures you won't get that chalky crackled look. In comparison to Lumene beauty base it is superior; staying power is much longer - I would say approx 3x- and unlike Lumene TFSI does not oxidize!
Out of these three primers TFSI is the only one meeting my expectations; it does the job without irritating my skin or eyes, it's great value and very easy to use. If you're debating getting a primer I suggest TFSI, it is simply the best.
I would buy this again and recommend to everyone!

I bought this as an afterthought and almost regretted my purchase. Funny, as now I use it every single day I wear eye make-up! And, cannot even remember what I originally purchased with it.

I have hooded, deep-set eyes w/ tiny, oily lids...but I love eye make-up.

TFSI is great. Originally, I wanted it to be more opaque / cover my eyelids better, concealer-like. But, now I really really like it just the way it is!

If you have "difficult" eyelids like me, wait 30 secs after application, looking downward. Keep the eyelids as smooth as possible. Then, apply your e/s. (Because if you get a crease on this stuff, I guess you are stuck with it for the day!)

My e/s sticks with me beautifully with this stuff. LOVELY.

And, I am very particular about hygiene, so I love stuff that comes in tubes versus tubs.

Will re-purchase!

I wore this under my eye shadow on a day that involved a long, sweaty commute (hot subway platforms, running for trains, etc.), then an hours-long concert where I was dancing and sweating. ALL my other makeup had melted off my face - foundation, powder, blush, even lipstick - but my eye makeup looked freshly applied. I've been wearing it every day I've worn eye shadow ever since. Two thumbs up.

I'm in love! I bought this from e-bay for about $13.99..I put the price as a 2 because you only use a tiny drop for each eye. My eyeshadow lasts and lasts :). I took a nap yesterday and my eyeshadow didn't make it through but oh well hehe

UPDATE: I had to come back and give this 5 lippies! Its just that good ;)

This so far is the only primer i've used that doesn't cause my eyeshadow to crease after about 4 hours.
I work in shorter shifts, but i'm at school for about 8 hours a day and I really can't redo my eye makeup in the middle of the day. This stuff makes my eyeshadow look just as pretty at the end of the day as it did when I apply it and the packaging is amazing. I didn't spring for UDPP because of the complaints about the packaging, and honestly I don't know why they don't just put it in a nice simple tube like this.
Since they are about the same price, you can bet i'm going to buy this no-fuss stuff everytime rather than UDPP.
And I would buy it again, though since it's expensive I hope this lasts me a good long time

I love this stuff, when I went out to a club or party, my eyeshadow would always crease, fade, smudge, etc... now it stays put all night, I can sweat, dance, do whatever. It lasts me around 14 hours and doesn't crease. The only thing I don't like is the industiral smell it has, like plastic.

luv this product!! doesnt make my shadow crease & last all day continued >>

It didn't work for me. I don't know why it didn't but it didnt. I could say that the packaging was easy to use but that's about it. It didnt prevent creasing and it didn't make my shadows look any better. The texture is very thin and liquidy. After some uses I noticed that the eye primer started to separate into oil and a peachy texture. I tried shaking it but it was still the same so I just threw it out. Not worth it.

Where have you been all my life?? This is an AMAZING product. I contemplated between this and the UDPP as most other people mentioned, but decided upon this one cuz the packaging just seemed more convenient. I bought it today, tried it, and upon looking at the results decided to immediately write a review. I was hesitant buying this at first because I don't really have problems with eye shadow (since I don't use a lot or I guess I just don't have oily lids) but my eyeliner would always smudge. I would apply eyeliner to my lower waterline and within an hour or two it would disappear. But NOT today! I didn't know if this product would work for eyeliners, but decided to give it a try. It's been about 7 hours since I first put on eyeliner and it hasn't budged at all. AMAZING. My eyes look exactly how it was 7 hours ago. AMAZING. Totally worth the $17, and I heard it lasts forever. I've never been so happy with a product before. AMAZING.

I'd been deciding between this and UDPP for the longest time, and finally got this because the packaging seemed better than UDPP's. I was pleasantly surprised to find that my eyeshadow lasted for 8+ hours outdoors with this, it definitely outperformed my expectations! Definitely worth the 17 bucks because you only need the teeniest bit per eyelid, so it will last quite a while.