Developing the Sliver

The design of the Sliver, a new yoyo from Mk1 and Spiral, began with a threat.

anyhow if we're gonna collab we should think of some sort of idea or theme or concept
you have 5 minutes. otherwise I'm making you pay for half a run of The Spin top return top tri-material bimetal disaster

Jamie (Spiral owner) immediately responded with some slimline/mini thoughts, and a 37mm wide concept that he had been working on intermittently. This was back in 2020, early in the year, before even the Kappa had released.

Talk about a collab subsided for a couple months, interspersed with design questions like, “how wide do you think a bimetal could be before it blasts itself apart?”. I got distracted and worked on the Exia, and some counterweight ideas. Jamie was working on the P40-Warhawk. We traded ideas and tips back and forth. He was preparing for the Kappa release, I had just dropped the Umbra. We talked about yoyos a lot, philosophically.

(junji ito comic)
Hmmm... I'm sure this was formed by the earthquake as well.
But unlike the one on the other side, this one's quite small.
Aha! Take a look at this!

There are holes, but they're not yoyo shaped...
Don't really have any form...
How b-grades are made

In May, we got back on track, looking up different slimline widths, and found a range to explore between Heshgod Petri (28mm) and SF 36 (36mm). I made this rough draft:

3d yoyo render
Early slimline draft, 57×34

Jamie sent me his version:

3d yoyo render, profile
3d yoyo render, cup

We go back and forth like this for a couple hours until we take a break to think of a name for the collab. Mostly we found cool names that had already been used on other yoyos. Since we’re pals, I bought a Kappa and he bought an Umbra. We like each other’s yoyos, which is a good sign, always. We traded some MTG anecdotes with each other, which I suppose is an omen of things to come! Plus, this important exchange:

I want a good slimline unresponsive that isn’t punishing

– me

bro yes let’s make a GOOD slimline

– jamie

Several months later (July 2020), Jamie sent me a file called “heck.x_t” which contained a yoyo design.

Sliver early revision

I sent back a revision where the rims were rounded over.

Sliver early revision

We didn’t even have a working title for the yoyo, having abandoned plenty of great ideas that were already in use.

Its frame is made of lead and it's 5 times the weight of a normal yo-yo. I call it... THE HEAVY BRAIN  !!

Heavy ... Brain  !!
Case study on yoyo names

Eventually, finally, we thought of something passable: “dither”, referencing a pixel art technique where two colors are blended using a checkerboard or other pattern, which adds texture + the appearance of a third virtual color. It’s a metaphor for how we created the yoyo, of course.

Through this process the design got refined down to something really close to what you see in the production version. 6061, flat cup, same dimensions. We discussed the ‘small’ 8mm axle and decided to simply put it through a stress test once we got the prototypes.

We were happy with it, our teams were happy with it, so it was time to order some. So, I did. And we got the first prototype photos in August, along with the Mk1 Contact, which I was prototyping at the same time.

Sliver prototype photo
Sliver first prototype
Sliver prototype photo
Sliver first prototype

Later, they came in the mail.

Sliver and contact prototype sets
Contact and Sliver prototypes

We sent them to the team for feedback, and got a couple notes that resulted in changes for a 2nd prototype. Of note, the weight dropped, the rim cut in the profile got pulled back a bit, and some of the fillets were made more round. The next round of prototypes were blue rim dip, just to try something new. It took a bit to get around to this, due to other yoyo releases, but in February 2021, we placed the order. This is also when Jamie came up with the final name for the yoyo:

yojamjam: Yoyo name. This is the one I think. Sliver

The 2nd sliver prototypes arrived at the same time as the 2nd Contact run. They looked cool! I shipped them out for team testing and got to work on the other various MK1 stuff that I had been putting my time into.

Blue yoyos
Sliver 2nd prototype

The CAD file ended up not changing from this version, but the other really long part of yoyo production was still left – picking colors, designing engravings, coming up with a box & a sticker. This was a collab, and a special one, so I wanted to get really deep into it.

Given the new name & theme, I contacted one of my M:TG friends who had been working on card proxies, and hired her to design box art based roughly on the look of Tempest pre-con decks. This was combined with custom art from a friend-of-a-friend.

Magic the gathering
The rath cycle (tm)
"The Slivers" Preconstructed deck
Magic: The Gathering Preconstructed Deck
Sliver artwork
Custom Sliver artwork by Sheyenne Smith
Box artwork
Box art by Evelyn Butler

The box was designed to fit Magic cards, though it’s thicker than usual to accommodate the yoyo.

For colorways, we settled on making some raws, 2 rim masks, 2 fades, and 2 solid colors. This sort of symmetry makes the reasoning process easier for me, and also provides a handy way to organize the yoyos once they arrive. Of all the colorways, the PK Sliver took the longest to develop, due to the newness and intricacy of the engraving. It’s striking in person, and we all hope you enjoy it (or whichever colorway you get).

The colorway development process usually involves tons and tons of 3d renders, which I’ll spare you. Instead, here’s a photo of the results.

Sliver colorway photo
Sliver production colorways

There we go. That’s the tale of the Mk1 x Spiral SLIVER yoyo. I hope you enjoyed it. Maybe you can be part of the story?

This yoyo releases on Friday, January 21st, at 8PM Eastern right here on and on Throwspiral dot com. (Also yoyoexpert, yoyosam, yoyotricks, and yoyoworld)

Mk1 and Spinworthy – The RBC

The RBC yoyo is a collaborative effort between MK1 Yoyos and Spinworthy. The idea behind this project was to take one of Spinworthy’s popular wooden models, the Blood Cell, and recreate it in high-quality 7068 alloy as a hollow, tug-responsive yoyo.

The RBC uses a very small MR85 bearing, 5x8x2.5mm in size, and custom pads that take advantage of the small diameter of the bearing. The gap is narrow (2.3mm) to keep it very snappy, making it pleasant for modern responsive stall-based play, shoot the moons, and for classic yoyo tricks.

MK1 team member EOS has a signature colorway of the RBC. Check it out!

The RBC yoyo is available here on MK1, and also at YoyoExpert, YoyoSam, and

rbc yoyo next to a cat


Mk1 team member EOS44 has been very, very busy in the yoyo tutorial sphere with great intermediate to advanced content.

Here’s some recent videos that we recommend!

Make sure you subscribe here.

Mk1 Contact 2nd Run – Releasing July 30th

It’s back! The Mk1 Contact yoyo is re-releasing July 30th at UK Throw, YoyoSam, YoyoExpert, and YoyoTricks. Find out more about the Contact or watch a review or two.

The Mk1 Contact will be $45 for solids and $50 for splashes/fades/dips.

photo of five mk1 contact yoyos sitting on a rock

This release includes five all-new colorways for the contact, including two signature colorways for Mk1 team members Connor and Luis. Show your support!

All B-grades will be available here on the Mk1 Shop the week following the release for a discounted price.

Mk1 Yoyos x Luis Lizardo

Luis is a friendly, supportive person who makes everything around him more positive. I first met him when I was starting out my own yoyo journey, back when I was making and trading hand-made yoyo strings with people. I even made him a terrible metal string that he apparently never received.

Last year, we got talking again, and things lined up to where we wanted to work together in yoyo. I’m very excited to present: Luis Lizardo.

Make sure you follow Luis on Instagram.