Protect exposed wooden stairs during the construction phase - which wood is best?

Hey guys,

we are getting two straight exposed concrete staircases that we only want to seal later. The protection of the stairs during the construction phase is on-site responsibility. So moi.
The following is planned: wrapping the staircase with a self-adhesive stair protection fleece and then casing the steps with wood. That means having it cut to step width and tread surface as well as width and riser, and then screwing it into the edge from top to bottom. (Plus of course lots of warning signs in all the languages spoken on our construction site )
My question: which wood should I use best? It should fulfill the purpose but please as cheap as possible, since it will be removed anyway. Have OSB boards cut accordingly?
Or does anyone have a much better idea for stair protection?

Thanks in advance!

We had the carpenter build something for the same purpose. He charged 300 EUR for it.
A cut was made from chipboard for the tread and riser and connected with strips, so the entire staircase was wrapped. Thin cork material was laid underneath to prevent the chipboard from rubbing too much.
There were signs in all languages as well. It worked!
The stair protection served well for several months! You might be able to see it a bit in the photo.
In our case, it was not a precast concrete part but poured on site. The foreman did an excellent job! So far the stairs are still completely raw, as they came from the formwork; we haven't gotten around to plastering yet and somehow we have gotten used to the construction stairs.
What do you want to plaster with?

Had impregnation done by the concrete plant and ordered packaging as well. Basically a formwork made of construction wood with a tarp underneath. What kind of filler? The concrete is smooth formwork. If you apply filler over it, it’s no longer exposed concrete.

Yes, that's exactly how we have planned it now. First a kind of padded foil, then formwork with OSB cut to size. I’m doing it myself and it costs me about 120 material. There will be no puttying at all, as wrote. Only sealed. Would you like to show your stairs?

Since the concrete was poured on site, the surface is not as perfectly smooth as with exposed concrete stairs from the factory. It should - in the long term - still be treated with [Beton Cire], which is applied at a thickness of 1mm. However, we are no longer so sure whether this should still happen or if it should simply be sealed.

Yes, okay, but then it is not exposed concrete. Hence the confusion.

The order for Beton Cire is so expensive that a prefabricated part would be considerably more cost-effective for us.