Plastic boning is fine. In fact with the sheer number of costumes needed to be made you'd be surprised how much it is used in the film industry Just make sure you use a good brand, and use as much as you need too. I mean I use a good 6m in my corsets and even that isn't as much as used in real whale bone corsets. As this corset is made to be very straight up and down you'll need to iron it flat. The curves from being coiled are wonderful for making hourglass corsets where you want the top and bottom to curve back in to the body, but for this not really. You need to lay the boning between two pieces of cotton, or even better in the boning channels of the corset and you simply iron over them. If you lay them so the ends touch the board but the middle curves up from it it is better. What does help is if you are able to lift one end off the board to reverse the curve and iron too. Then you let them cool down and voila. Nice flat bones I use a mix of excellent white german imitation whale bone, I think farthingales or grannd garb stock it, and a cheaper quality polyboning that is clear and ridged (*not* Rigiline). Used properly plastic boning is the best substitute for whale bone there is as it behaves very much like it. There is a certain degree of molding to the body with it, but it is very easy to simply iron it flat again if needed. Rigiline on the other hand is a pain to work with *if* you are making a long corset like this. I've heard good reports of it for conical corsets like in the 16th-18thCs but that is because they are not pulled in twists and curves like in a long corset. I had to iron a corset practically every night for a fellow actor who had to put up with a long corset made from the stuff... Mind you if you zig zag two layers of rigiline it will work too. That is if you are in a rush and cannot get the other stuff, it is possible to use it well that way.