Where does Cloth-Head come from?

Solution 1:

Glossary of Yorkshirism

Clothead – stupid person

Words in Time and Place: Exploring Language Through the Historical Thesaurus of the Oxford English Dictionary

clot - A middle-class colloquialism for 'fool', but also found widely in dialects of northern England and Scotland in such forms as clothead and cloit, as well as in earlier 'blockhead' expressions as clotpoll (1609). It is often no more than a mild or friendly term of abuse, frequently with a nuance of clumsiness, as in the expression 'clumsy clot!'

Looking at clotpoll/clodpole:

Etymology clod +‎ pole (“head”)

and further clod

Etymology From Middle English clod, a late by-form of clot, from Proto-West Germanic *klott (“mass, ball, clump”). Compare clot and cloud; cognate to Dutch klodde (“rag”) and kloot (“clod”).

Examples

Laughing Boy: The engrossing Yorkshire crime series

"What do you want?" Dave asked, one leg out of the door. "Um, so something fast." "Gazelle?" "No, clothead! Cheese, salad, whatever. Something that's ready made."

Yandro 184

I figure this must be deliberate humor; nobody could be that much of a clothead, so I smiled non-committally.

A Son of Hagar, by Sir Hall Caine

"He's allus stopping short too soon," said Gubblum. "My missis, she said to me last back end, 'Gubblum,' she said, 'dusta mind as it's allus summer when the cuckoo is in the garden?' 'That's what is is,' I said. 'Well,' she said, 'dusta not think it wad allus be summer if the cuckoo could allus be kept here?' 'Maybe so,' I says; 'but easier said nor done.' 'Shaf on you for a clothead!' says she; 'nowt so simple. When you get the cuckoo into the garden, build a wall round and keep it in.' And that's what I did; and I built it middling high, too, but it warn't high enough, for, wad ye think it, one day I saw the cuckoo setting off, and it just skimmed the top of that wall by a bare inch. Now, if I'd no'but put another stone--"

Solution 2:

Possibly an extension of “clod-head” from “clod”, an old term for stupid person:

Clod:

(also clod-head) a stupid person, esp. a dull-witted peasant.

• 1599 [UK] Jonson Every Man Out of his Humour I i: This clod, a whoreson puck-fist!

• 1605 [UK] Jonson Volpone III i: O, your parasite Is a most precious thing, dropt from above, Not bred ’mongst clods and clodpoles, here on earth.

• 1882 [UK] Dundee Courier 27 Jan. 7/1: But we don’t a-know wot way he has gone, clodhead don’t yer see?

• 1973 [UK] B.S. Johnson All Bull 151: It surprised me, the odd clod apart, how easy it is to achieve this [i.e. military drill].

(Green’s Dictionary of Slang)

Solution 3:

Chīnt in Hindi means speckled, spotted, or variegated. The name of the fabric chintz, which originated in Golconda/Hyderabad, is derived from this Hindi chīnt to describe the its typical patterned design. Source.

Meanwhile in Bangla, "mathaye chhit" is an insult that roughly translates to cloth-head (but specifically this spotted, speckled cloth). It usually connotes eccentricity rather than stupidity, though. I've grown up hearing the Bangla phrase used quite frequently and was once told that its literal translation was "cloth in your head," but I'm not able to find an online source to corroborate this.