I invented pull-to-refresh.

I worked at Apple on the original iPhone.

I wrote a programme called Tweetie,

which was sold to Twitter, and became the Twitter client

for the iPhone.

I worked on a game called Letterpress.

And now, I'm one of the creators of the Ragmask project.

And can you tell me what that is?

What the Ragmask project is?

The Ragmask project is a set of extremely simple, extremely

fast-to-manufacture plans for face masks.

Why did you decide to do this?

We had a sewing machine.

And I tried following a few of the plans online.

And I'm not an experienced sewer by any stretch

of the imagination.

So we just developed something that

was much simpler to create, something that I could follow.

Like that was the design constraint.

Could I do it?

This is one of my first sewing projects.

I guess my philosophy is, I can't think about something

without using my hands.

I mean, it's the same with programming.

It's the same with fabric.

It's the same with wood.

It's the same with anything.

So if I can get some fabric in my hands and a sewing machine,

and you basically just like iterate

over and over and over and over again,

eventually good ideas will fall out of it.

And this particular shape of mask

just happens to be extremely easy to make.

And it fits pretty well.

It's not finished yet.

We have like two or three more versions coming.

And I'm thinking of it more as a technology product rather than

a garment.

We're literally versioning it.

We're up to version 2.2, 2.3 is coming tonight.

3.0 is coming next week.

And they're each going to be refined in some way.

Do you have one of the masks there, by any chance?

I do.

I don't have one of the ones on the website now.

But I have one of the ones that I'm working on.

We're trying to make it even simpler to make.

Straps...

we can't find elastic.

Everyone's out of elastic.

You can't even buy it online anymore.

So that's why we call it a ragmask,

where literally, you can make it out

of rags, dish towels, sheets, old pillowcases.

So this one, where we're telling people, it's not out yet,

but we basically just put loops on the ends.

And then people can take shoelaces, or anything else

they have.

We're going to deliver masks without any straps at all,

and they're going to supply their own straps.

And it saves us a lot of time and material.

Can anyone make these masks?

And what do you need to make them?

Really, all you need is a needle and thread,

and some old fabric, any fabric.

A few people now have hand-stitched them.

It takes a little bit longer.

If you have a sewing machine, it goes a lot faster.

You really want to wear any kind of mask.

Even if you don't have a needle and thread,

there are tons of designs out there.

The CDC just put one up.

You can fold up anything with two rubber bands

and put it behind your ears.

I mean, that's more effective than nothing.

How do you know that these masks are effective?

A lot of the benefit isn't necessarily

the filtration ability of the mask.

Because you're not filtering the virus itself.

You're filtering out droplets, which are much,

much larger than the virus.

But you're reducing the radius of aerosols

coming out of your mouth and infecting one another.

We started the project before the CDC

and the World Health Organization

were recommending widespread mask use.

So at this point we're relatively

confident that they're effective in some way.

On the wider public perception of mask wearing,

can you talk a bit about that?

Whether you think everyone should wear them

outside or not?

I feel like most of the people watching this video probably

aren't wearing pants, because everyone's at home.

Like, no one can tell if I'm wearing pants right now.

But culturally, if you do have to leave the house

- which you should avoid - you would put on pants.

And I think the shift that needs to happen

is if you put on your pants, you should put on a mask.

And if you're the only one wearing pants,

that's not enough.

Everyone else needs to be wearing pants.

Everyone else needs to be wearing a mask.

You should get weird looks if you're not wearing a mask.

That's the way I think about it.