There are so many terms for work jumpsuits, overalls, boilersuits, onesies, boiler suits and coveralls: We'll just use Overalls here:
Generally people prefer zip fasteners, except if there is a heat/fire risk. (If there is a strong likelihood of fire risk, buy our FR overalls - which have suitable zips that are covered and not likely to stick closed).
For regualr work overalls, Polycotton is often favoured over cotton - because the polyester content:
1) holds its shape and doesnt tend to shrink in the wash,
2) is more durable than pure cotton and
3) is more colourfast
Polycotton coveralls are also available as hi vis overalls, with reflective tape on the arms, legs and shoulders - such as the Wenaas two tone polycotton boilersuits which look smart and are certified to EN 340 for your safety.
Looking for a short sleeve lightweight coverall? suitable even for tropical climates: orange short sleeve, lightweight coverall.
Many overalls, like this Wenaas two tone royal and yellow coverall are triple stitched these days - for greater longevity.
For polycotton thermal winter padded overalls, look no further than Black Knight Navy padded coverall.