  We prove a conjecture of L\^{e} and Sikora by providing a comparison between
various existing $SL_n$ skein theories. While doing so, we show that the full
subcategory of the spider category, $\mathcal{S}p(SL_n)$, defined by
Cautis-Kamnitzer-Morrison, whose objects are monoidally generated by the
standard representation and its dual, is equivalent as a spherical braided
category to Sikora's quotient category. This also answers a question from
Morrison's Ph.D. thesis. Finally, we show that the skein modules associated to
the CKM and Sikora's webs are isomorphic.
