The image above, Orchids on Black, was created by photographing the flowers on a black background, with a bit of enhancement in LAB color. Flower Magic on Black, shown below, was photographed on a light box. The background of the image was converted from white to black using an LAB inversion of the L-channel.
Click here for my complete Creative LAB Color in Photoshop course, here for the FAQs on my website, and here for info about the 2020 session of the Photographing Flowers for Transparency workshop.
Special thanks to Jack and Ellen Anon.