He tries it, checking with Rabka to see whether he's doing each step right, and successfully ends up with a clove-hitched segment of yarn!  The next time he skips the checking and puts the yarn on the wrong side of the latch before correcting himself when it fails.

"Oopsie. Let's unpick that one." Pick pick.

He does the next one correctly, and the one after that, and then enough more that it becomes clear he's starting to work faster than is nonmagically possible.

"Wow. You go real fast. I did this every day for years and years and I'm slower than that by a lot."

" - Mm.  Looks like it's a valid magical medium, then."

"Cool! What does that... mean? Like, is there anything you can do with it that you couldn't do with what you already had?"

"Versatility never hurts, and from your perspective if a tattoo does let you use magic then I imagine you'll be better at something you have more experience with."

"Will I be able to do it super ultra fast?"

"It's possible."

"Not everybody who can do magic can do that?"

"Little children and adults without much experience only go as quickly as they would working on similar non-sewing tasks; the fastest the most powerful seamsters can work is a day per hour.  I don't know whether your previous efforts would already count or how powerful you would be if they did."

"Well, I guess that'll be exciting to find out. Does it feel like a day, when you do a day in an hour?"

"It feels like . . . a day of the most engaging and fulfilling work it's possible to do.  It's not really something you can get tired of.  At least while you're doing it."

"Ooooh."

Cathei yawns awake, and, wonder of wonders, does not immediately nuzzle her mom. Rabka holds her out.

" - I can hold her?"

"Yup! Quick, before she gets hungry again!"

Baaaaaaaaabyyyyyyyyyy.  He takes her.

She's soft and small and warm!

She is!!!!!  And she will be held and rocked and lightly bounced until she seems to not want that anymore!

Eventually she will nuzzle him and Rabka will hold out her arms. "That means she wants milk."

The baaaaaaaaabyyyyyyyyyy is returned.

"You like babies, huh?"

"I guess so."

"You gonna have some eventually, do you suppose?"

"I don't - know . . ."