Quessetéma was one of the four series of the Tengwar writing system specifically for the Quenya language. As with all of the series it consisted of six characters in each of six tyeller or 'grades'. This particular series took its name from the first of its signs, quesse (literally meaning 'feather', but here simply the character representing 'kw').
Unlike Westron or other languages, Quenya needed a series of characters for labialized consonants. Quenya writers used the third series of Tengwar characters for the Calmatéma (the k-series) and the fourth series for the Quessetéma (the kw-series). In the Quessetéma, half of the symbols had one bow or lúva while the other half had two bows. All bows in this series curved upwards and to the left from a stem, or telco, which was either lowered, raised, or shortened, and all of the bows were closed with a bar across their opening.
The names of the letters in the Quessetéma were established in Quenya and had become standardised by the Third Age. The first four signs in the series were quesse, ungwe, hwesta and unque, representing 'kw', 'gw', 'khw' and 'ghw', respectively. The fifth sign, nwalme (earlier ngwalme), represented 'ngw', while the sixth, vilya (earlier wilya) was used for 'w'.