Kindly see this text: MAT release, matte release, syndicated content, advertorial — however you spell or say it, this PR tool is meeting the needs of the shifting landscape of America’s newspapers and media outlets. (https://www.brandpoint.com/blog/what-is-a-mat-release/)

and: MAT Release articles subtly weave in relevant brand messages to informative and entertaining content in a variety of topics, including; Home and Garden, Health, Food, Personal Finance, Automotive, Travel, Education and Careers, Weddings and Seniors. (https://www.brandpoint.com/content-marketing-services/paid-e...

So I think mat, matte, subtly weave evidently contain a common sense, i.e. they refer to something woven into other things.