Well, I'm back, and I need to sum up the relevance of the two preceding posts about IP to UK crafters.
First of all, the good news – you have a considerable degree of free and automatic protection for your work, be it 2D or 3D, as long as it is original. Copyright and design right both come into play automatically and work in your favour.
HOWEVER, the emphasis is, quite rightly, on originality.
You do not have protection for your work from either copyright or design right if it is not original, and design right offers no protection for a 3-d article which is 'commonplace, everyday or ordinary'.
If an item is 'commonplace, everyday or ordinary' it cannot, by definition, be original.
In other words, you'd better be very sure indeed of your having something really original and 'different' before you try to stop other people making something similar – whether from a pattern you've published or not. Anyway, isn't imitation the sincerest form of flattery?
Much better-informed minds than mine have debated at length in courts of law, and elsewhere, as to whether the use of a pattern -without specific permission to do so - for the production of items for sale is permissible or not. Consensus seems to be that it might be, or it might not be. Helpful, no?
There are endless debates on t'internet regarding 'originality'. It is perfectly acceptable – indeed common practice and considered polite – to acknowledge that inspiration from a designer or a specific design has been the foundation of your design.
So, some people ask, if they change an existing pattern so the finished item is not the same, how much do they have to change for it to be considered 'original' and hence 'their own work' ?
If someone (you?) is capable of changing a pattern or plan sufficiently that it results in a different design, you are surely capable of making your own pattern or template after looking at the design you like instead of blatantly copying!
As ever, I am not a lawyer nor do I pretend to be one. If you have queries, contact a suitably qualified person and/or do your own research. I am in the UK and my posts can only be considered relevant only to the law in England and Wales.