Sample boxes: any number of samples for one price, for example any 5 swatches for 10. A box drawer with a progress bar shows on shop and product pages.
Sample sizes: offer more than one sample of a product, such as an A5 swatch or a 1 metre cut, each with its own price and stock. Shoppers pick the size next to the button.
Free samples: make every sample free once the full products reach a cart total, or make one sample free with every full order.
