WE DO NOT RECOMMEND THE USE OF ROYALTY FREE SAMPLES BECAUSE OF THE HIGH NUMBER OF COPYRIGHT INFRINGEMENT PROBLEMS OUR CUSTOMERS HAVE FACED.
Regarding Royalty Free samples, it is important to take into consideration the conditions given by the sampler (e.g. that it is allowed to be used for distribution and for profit) and to have documentation (links to the product page for example) where the conditions are correctly indicated.
Consequently, with the use of royalty free samples, releases may not be accepted/submitted to Youtube Content ID or other portals for example.
Finally, if a release is using royalty free samples, it is best to let us know before it is submitted (along with documentation to support the above).
Not all portals accept releases with royalty free samples, keep in mind that the use of these samples is massive and other artists may use the same samples and register them as their own and may sue you for copyright infringement.
To avoid all these situations we recommend not to use royalty free samples.