Very pretty color.
I loved my inks and book. Great service.
Let's start off with the positives. This ink is absolutely a delight to the eye. As others have stated, it does swatch quite a bit differently than it writes. It also takes on a radically different appearance depending on the quality of paper. I used it in a TWSBI Vac700R with a medium nib, and it wrote very smoothly, dried in a reasonable amount of time, and produced a very attractive red sheen on Clairefontaine 90 gsm paper. On the cheap Mead notebook paper I use to write meditatively, it did not demonstrate any sheening qualities, and took on a much greener hue that I can only describe as being akin to green marine grease. While that may not sound appealing, I actually found it to be a very unique, subtle and pleasing color with which to write.
Unfortunately, that is where the positive attributes of this problem child ink ended for me. Nothing can contain it. It somehow manages to bypass rubber seals, insinuate itself into the threads of any joint it encounters, and stains rapidly. I only had it in my Vac700R for a total of 12 hours and five written pages before I opted to nuke it from orbit. In that time, it somehow found its way out of the feed's ink channel and into the fins, resulting in stained fingers and dripping ink as I wrote, as well as into the threads between the section and barrel. These seals are impervious to every other ink I've tried so far, but not Sheen Machine. Thankfully, the TWSBI is easy to fully disassemble so I was able to get every nook and cranny clean and inspected to ensure I didn't have a crack somewhere which was the true cause of my seepage woes. I have since run a number of more mundane inks through the pen with no repeat of the behavior exhibited by Sheen Machine. I will have to try soaking the body parts in pen flush to remove the staining where it got into the threaded sections.
TL:DR - Dang, this is one pretty ink, but I will be reserving it for dip pens only going forward.
When you swatch this color it is quirky and fun to look at however please be aware that the shimmer will not come through as strong with the finer nibbed pens. I have tried writing with an extra fine, fine, and medium nibbed pen and it wasn't until I used a dip pen that I actually got to see the full effect of the pen ink on the papers that I was writing. Definitely a good buy and I love that the sheen sneaks up on people but I wanted to warn people who may not know that they need to use their widest nibs to get the full effect.
Fell in love with this ink at first sight. I just love how it stands out with all that sheen!