Technical term needed

[Super Firebug]

I'm in need of some of those stiff, cardboard (or pressboard, or whatever the material is) things that you sometimes find in looseleaf notebooks, that push the pages out from between the binding rings and the covers when you close the notebook. But I don't know what to look for online, because I don't know what they're called. All that I can think of is "paper-pushers", and I know that that's not right. Might someone know the term that I'm looking for? I could make my own, but I'd still like to know what they're called. Thanks for any help.

[crashpositron]

https://www.amazon.com/b/ref=s9_acsd_hfnv_hd_bw_b4UF2_ct_x_ct08_w/145-6041036-3690631?_encoding=UTF8&node=490549011&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=merchandised-search-3&pf_rd_r=A0MWGRX76T5J7WF72188&pf_rd_t=101&pf_rd_p=e44db49c-c4db-5464-b229-7aa63784217b&pf_rd_i=1069564

[Vee]

should go with the boomerang ones in case some dingoes or angry kangaroos happen by.

[Super Firebug]

Thank you! (I love the Internet!) And I hadn't even known that any types were made other than the plain, straight ones that I've always seen.