I wanted to know whether rigid white UV ink would hold up on a flexible leatherette bookmark, and where it would start separating once the bookmark bends.
I print the bookmark on the xTool O1 Omni, look it over flat, and then bend it hard to stress the printed area. That way, how it looks and how it handles flexing are two separate questions.
It took about two and a half minutes to print and roughly a quarter of a penny in ink. Both the amount of ink and the artwork layout affected the result, and a hard bend shows the tradeoff compared to flexible white.
Rigid white may be fine if the product won’t bend much. But I’d test your exact blank, artwork, and ink setup for how it’ll really be used before you sell a flexible printed product.