Most exposure systems are designed to work on averaging the lighting ,and even sophisticated cameras can get it wrong. If your camera can add some extra exposure using the + setting on camera or menu, that helps. Some have a white balance control and that might help, but alters all the colours, so be careful. I use a range of materials including satin, velvet, etc, and they work well. Software colour balance adjustment in Photoshop Elements helps too.
By the way, green foliage can work brilliantly for ceramics and larger objects, I used that technique for a lady who makes mosaics.
I always prefer the green foliage backgrounds myself I get a much truer colour balance.
I have tried numerous backgrounds and found that my best pics are when I photograph an object in natural light against a piece of white felt - for some reason felt photographs really well. I donāt do the pics in direct sunlight as thatās when you get shadows, but just close to the window so you donāt need a flash.
I used to take ages trying to get decent quality pictures of my jewellery. Either the colours didnāt come out true with some of my anodised aluminium pieces, or things came out too dark or with too much reflection on them (especially with polished silver items).
I just bought a small photographic light box from eBay for 39 pounds and it has made taking photos so much easier. It has a built in light. The lighting is perfect every time and there is a choice of backgrounds. Iāve only tried the white so far, bud thereās a graded dark to light grey one and a sort of gold colour one.
Obviously this is only good for small items,though I think you can get bigger ones. Hereās a photo of what it looks like.
Today was the first time I took photos of my products, normally my husband is the photographer in our house. He set up everything for me, so it was fairly easy. Here is a picture of the set up: