1970 Challenger R/T SE 383 4 spd FF4

[6bblgt]

I don't believe there is any factory literature that calls out the cloth seat patterns (probably called out on an engineering drawing or equivalent)

just like "boar grain" vinyl tops or "ledger green" stripes, it was simply "black vinyl top" or "green stripes" in sales literature

"houndstooth" for example is a universal pattern that would mimic the above pic - "salt & pepper" or "checker board" on the other hand, I believe, are invented descriptive names
& "ledger" green was left to be named by the restoration aftermarket to distinguish it from "chartreuse" or other greens, etc.

"PLAID", well, is easy! 

[MONC]

Got it , makes sense.

Regarding the orange plaid inserts, there appears to be  a houndstooth pattern within the design as well, that's why I always called it orange houndstooth as opposed to just orange plaid as Daisy Duke is nicely showing off 

[anlauto]

I think they ALL look cool...Get so bored of seeing plain black seats in these cars...

[MONC]

Agreed Alan.
I like the 70 cloth inserts in blue and in green, sets off the interior nicely.
The black and white houndstooth with the red trim on the Barracudas in 70 are awesome as well.
And don't get me started on the mod interior , crazy ! 

[RUNCHARGER]

I agree, cloth inserts look great and sure make driving the car more enjoyable.