Most private-label cat products fail for a boring reason: the shape was decided by what looked good in a drawing, not by what a cat will do with it. A scratcher that tips when a cat leans into it, or a bed whose opening is two centimetres too narrow, will not sell twice — no matter how good the print is.
Before artwork, settle four things: the shape, the board, the print and the pack. Everything else follows from those.
B-flute is the usual choice for flat pads and refill cores: thin, dense and cheap to ship. BC double-wall suits lounges, houses and anything a cat will sit inside, because it holds a shape under weight. E-flute takes a finer print and is worth it when the surface is the product — a pattern, a photo, a brand mark that has to read clearly.
Density matters more than thickness. A tight, high-density board with a clean edge will outlast a thicker, looser one, and it sheds less dust onto the floor.
Ask for the structure sample before the printed one. A white sample tells you whether the folds close properly, whether the piece stands on its own, and whether the proportions work in a room. Print can hide a weak structure for a week; it cannot fix it.
When the printed sample arrives, check the cut edges, the glue line and the fit of any inserts. Those three details are what a buyer sees first on a shelf.
Send the product type, the size range, the board you have in mind, the print treatment, the packing format, the target quantity and the market. That is enough to quote and to build a first sample. If you only have a reference photo, send that — it is a starting point, not a limitation.