And sometimes a problem for those wearing it, as war rages between Israel and Hamas militants in Gaza.
Activists say police in France and Germany - which have cracked down on pro-Palestinian protests - have cautioned, fined or detained people sporting the chequered scarf.
Supporters of Israel see it as a provocation and backing for what they see as terrorism.
This is what the keffiyeh means for protester Stefani Costa in Lisbon.
"It means resistance, the struggle of people who somehow resist colonialism, which is something so brutal in which you lose the right to your land, your history, your culture. So I think it carries that weight, the weight of freedom, real freedom."
Ramy Al-Asheq, a Palestinian Syrian poet who lives in Berlin, says people were being asked to take off the keffiyeh.
He found this way round the problem - getting one tattooed onto his arm.
Israel supporters say wearing the keffiyeh shows a disregard for the 1,200 Israelis killed in a cross-border raid by Hamas militants on October 7, which triggered Israel's assault on Gaza.
Asheq and others point to the more than 18,000 people killed in the offensive and Israel's continued occupation of Palestinian territory.
"Ever since the war in Gaza started it, like so urgent for me that this is the time because of all the criminalization of every Palestinian symbol, the Palestinian flag, the keffiyeh seen as a symbol of terror and being criminalized like Arabic language everywhere. So I thought like, now it's the time for me. I want to have it now urgently."
The heated debate has descended to violence.
In Vermont in the United States last month, three college students of Palestinian descent - two wearing keffiyehs - were shot, leaving one paralyzed.
The keffiyeh, pronounced kufiya in formal Arabic, has long been a symbol of Palestinian nationalism.
Late PLO leader Yasser Arafat was rarely photographed without one, folded in the shape of historic Palestine.
In Hebron, in the Israeli-occupied West Bank, the looms are working full tilt.
This is the Hirbawi keffiyeh factory, the last on Palestinian territory.
Online orders have soared since Israel started striking Gaza.
With a monthly capacity of 5,000 keffiyehs, it will take years to fill the backlog of 150,000 people who have expressed interest.
That's according to Nael AlQassis, Hirbawi's partner in Europe, who spoke to Reuters in Lisbon.
"It was like switching the light on, you know, it was like we were selling very slow. And then suddenly we had the huge demand on keffiyehs that we cannot fulfil."
"In general, when there is a conflict, symbols play a very important role. And keffiyeh is not an exception."
The traditional headscarf first took on a political significance with the revolt against British rule in the late thirties, when rural guerrillas covered their faces with the cloth, historians say.
The black-and-white pattern came in the 1950s, they say, when British commander General John Glubb assigned it to Palestinian soldiers in the Arab Legion to distinguish them from the Jordanians' red-and-white.
It was later adopted by Palestinian militants.
As the Palestinian flag was banned in the Israeli-occupied West Bank and Gaza between 1967 and 1993, the keffiyeh grew as a symbol of the struggle for a Palestinian state.
AlQassis says the protests show the keffiyeh now transcends borders.
"When we see people go to the street and wear our keffiyeh, wear our own clothes, they wear them and they go to the street and they show solidarity with them. This gives us hope that, no, that these governments do not represent their people and their people are having something else to say. And in the future, hopefully things will work differently."
