upstands look good if they are only 100mm, walls must be completely smooth to paint, a splash back is a must behind a cooker either a coloured glass or a small tile as a splash back. Make sure you use a kitchen/bathroom paint on the walls and seal the upstands with a top quality mastic after painting at the top of them and your walls. Any excess mastic can be removed with wet wipes.

Glass would look good - give you a little reflectance without mirroring everything on the worktop. Also could be a subtle way to introduce some colour. If you use clear glass with screw back type fixings, then you can change the colour now and then by painting the wall behind if you're nervous about colour, or think you would want to change the look now and then. Another option is a stainless steel, which again would add in a little light reflecting but in a grey tone that would work well with what you have.

Yes sorry didn’t include tap appliance or nib. The tiles are from Al-Murads. A local tile place which you can barter on as they expect it. Our current kitchen and bathroom tiles were from there 14 years ago. Tiles called diamond Carrara Appliances are black Neff and tap Matt black. Just unsure if the marble effect worktop will clash with geometric style splash - they both seem such obvious styles in their own right. Love them both.

Oh, paint it. Personally I’d paint it a dark grey similar to the worktop so that the line between the two disappears, if that makes sense. It will tone well with the floor and make a lovely backdrop to simple accessories. You might need a fair number of coats, but I have had something very similar in two houses now—including behind the hob—and it has proved very resilient and easy to clean. Also, the wood provides a nice surface for sticking stuff to as the seasons change. I put tiny little Christmas trees (card decorations, really) on the border and this time of year. In the past I’ve stuck everything from ceramic plaques to pretty paper plates.