[LaPistola]

You don't have to register a business anywhere unless you are not a sole trader which you will be. For the amount of work you seem to be suggesting you will take on will probably not even reach the threshold to where the taxman can take money from you. I forget the correct sum or even the new threshold but it used to be around £5200. So you can earn upto £5200 a year before the taxman can tax you.

As long as you submit your earnings, losses or evens to the taxman each year you will be fine.

A legal business operated as a sole trader is only illegal if your braking health and safety or criminal law. You don't even need to be VAT registered until your turn over exceeds £72000 (again rough amount - I haven't yet done my tax returns for my last tax year).

Regarding Insurance don't take my word for gospel but I think you only need public liability insurance upto 1mil min which will cost you less than £100 a year I think. You may need product insurance if your making frames for your prints.

IMO ......... just do it. Good luck!