Many Dutch websites with genealogical records allow you to download scans. But it is not always obvious what you are allowed to do with these scans. You may want to upload them to your online tree, use them in a blog post, or include them in a book you’re writing. With most public records published on websites of archives, you will be able to do that free of charge and without the need to ask for permission.
The Dutch Wet Hergebruik van Overheidsinformatie [Reuse of Government Information Law] allows anyone to re-use public information for any purpose. Government agencies may only charge for the extra costs it makes to provide a copy. In the case of downloading scans from a public archive website, there is no extra cost to the archive when you download so it is free of charge. That means that in most cases, you can reuse a scan of a record that is published on a website of a Dutch public archive however you want.
There are also situations where public archives have non-public records. In the case of records that are closed because of privacy reasons, you will often not be allowed to make an image copy. If you are provided with an image copy, that is for your personal use only.
Another exception is a photo collection where the archive merely has a copy of the photo and does not hold the copyrights. In that case, the copyright holder can determine if and how you may reuse the photo. That will typically be explained in the terms and conditions (“voorwaarden”) or copyright notice on the website.
A great source for finding photos that you may conditionally reuse is Open Cultuurdata Search. The website allows you to search the collections of many different archives, libraries, and museums to find images that are available in the public domain or under a Creative Commons License.