De or het vakkleding?

The correct Dutch article is:

de vakkleding

Rule Words ending in -ing: almost always de. See the rule
Meaning (Dutch) specifieke kleding die wordt gedragen tijdens de uitoefening van een beroep. Het dient ter bescherming van de drager, hygiëne, veiligheid …

How to use vakkleding

the vakkledingde vakkleding
this vakkledingdeze vakkleding
that vakkledingdie vakkleding
our vakkledingonze vakkleding
your vakkledingjouw vakkleding
every vakkledingelke vakkleding
which vakkleding?welke vakkleding?
a big vakkleding / the big vakkledingeen grote vakkleding, de grote vakkleding

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).