Impart duty/tax is a complicated subject. On one hand, marking as gift is illegal if it's not actually a gift. But this is one of those laws that everyone breaks...and I can't see it being enforced on such small packages.
But it does set me up for legal consequences. And for the UK, the gift threshold before you have to pay duties on it is something like $60 usd anyhow...
So I mark my packages what they are, Original artwork.
The HR code for this category of goods is, 9703.00
From Canada to the UK there is no duties on this category, but a VAT of 5%.
On the Okin, you would expect a duty cost of about $8.25 usd
Of course, there could be some variation on this... like I said, Importing goods can be very confusing, and until I ship an Okin or two, I won't really know for sure.
The above information was based on a duties calculator, hopefully its correct!
Wht I will try to do Is make the shipping cost as low as possible for UK buyers, and absorb the cost of shipping materials, this should help offset the duties cost. Hopfully that sounds fair!