My brother and mother, grandfather, half-uncle and cousins all spell the name, Texidor. Josefa Texidor Torres signed her paintings with "Pepita Texidor". Modesto signed his paintings "Modesto Texidor". The Texidor shop run by Pepita's and Modesto's brother, Emilio (my great grandfather), in Barcelona still reads "La Vda de E. Texidor". The shop registered trademark reads "Casa Texidor". The plaque on the bust by Manuel Fuxa of Pepita Texidor reads "Pepita Texidor". La Vanguardia calls Modesto "Texidor".
However most sources in Catalan spell it "Teixidor". Going back through older and older sources of information I see variations in spelling - especially on much older tombstones - such as Texidó, which perhaps has also been mispelt as Teixidó. Spanish families migrated across to America over several hundreds of years; the spelling varies in America, but still Teixidor is quite a rare spelling...
In general the name is Texidor... but it's generally misspelt (with respect to my family) Teixidor in Catalan (and some Castellano) media, websites etc. It is also pronounced differently between Catalan and Castellano - (like Mexico) Texidor is pronounced /tek si dor/. Teixidor is pronounced /tay shi dor/. Texidó is pronounced /tek si do/ (with a slightly nasalised 'o' that sounds like a soft 'or') Teixidó is pronounced /tay shi do/(also with soft 'or' sound)
In Tossa de Mar, I found a new (or v. old) spelling on a tombstone: TAEXIDOR.