  We present a new publicly available tool (DustPol) aimed to model the
polarised thermal dust emission. The module DustPol, which is publicly
available, is part of the ARTIST (Adaptable Radiative Transfer Innovations for
Submillimetre Telescopes) package, which also offers tools for modelling the
polarisation of line emission together with a model library and a Python-based
user interface. DustPol can easily manage analytical as well as pre-gridded
models to generate synthetic maps of the Stokes I, Q, and U parameters. These
maps are stored in FITS format which is straightforwardly read by the data
reduction software used, e.g., by the Atacama Large Millimeter Array (ALMA).
This turns DustPol into a powerful engine for the prediction of the expected
polarisation features of a source observed with ALMA or the Planck satellite as
well as for the interpretation of existing submillimetre observations obtained
with other telescopes. DustPol allows the parameterisation of the maximum
degree of polarisation and we find that, in a prestellar core, if there is
depolarisation, this effect should happen at densities of 10^6 cm-3 or larger.
We compare a model generated by DustPol with the observational polarisation
data of the low-mass Class 0 object NGC 1333 IRAS 4A, finding that the total
and the polarised emission are consistent.
