If you are not happy with the finish then i'd suggest asking the plasterer to come back to remedy the work. You shouldn't need to sand down a newly plastered ceiling and should never have been advised to do that, another coat would probably sort the problem out.

You should never need to sand any new plastered surface.even with the artex scraped back I very rarely put a skim coat straight on.Majority of the time I will apply bonding coat first to guarantee a flat level surface and then apply the skim coat to give the client a prestine finishing surface for painting!

It sounds like the artex wasnt scraped back enough also he should have put two coats of pva then put a coat of carlite bonding over first then when dry. Put 2 coats of multi finish plaster over to leave a nice smooth finish. The plasterer needs to come back to pva and give another skim over.

Your plasterer has not done his preparations properly,
1) Scrape back high points of artex,
2) Good coat of PVA bonding agent
3) Light coat of Carlite Bonding undercoat plaster,
4) 2 Coats of Multi-Finish plaster.
This will achieve a great finish.
Any plasterer who tells you to sand his work down is not a plasterer, he's been on a course,
hope this helps you. Get the guy back to properly finish the work .

Hi guys..
would definitely recommend getting this plasterer guy/guys back to do your plastering works properly at no extra cost..

Any decent plasterer out there
Regardless the costed will leave you or any customer/client the perfect smooth flat finish ((With no sanding required))

A client should never have to (let alone be asked to) sand down any new plasterwork if it's done by a professional.

Get him back to sort it.

The plasterer who's done the job is not scraped the artex properly before he apply the coat of skim , now you need to re skim the ceiling and you will get a good finish if is done properly .