This depends on what program you have created your artwork with.
We suggest that you create all of your adverts in Adobe InDesign. The quickest way to resolve ink weight issues in this title is to export using a Newsprint ICC profile, which will ensure your artwork is in the correct colourspace and fix any issues with ink weight.
Adsend suggests ISONewspaper26v4 for Newsprint. For Magazines, we suggest adhering to the industry 3DAP (Digital Data Delivery for Australian Publications) standard.
There are various alternate solutions. If you require any further assistance, please contact Adsend Client Services.