Textures.com - Textures.com is a website that offers digital pictures of all sorts of materials.
Bannerbear - Auto-generate IG Stories, Pinterest Pins and more
Poly Haven - Poly Haven (formerly known as Texture Haven) is an online website where you will find scanned textures without any cost and that are of high quality.
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Poliigon - A library of materials, and HDR's for artists including free textures that want photorealism.
Placid - Use Placid to auto-generate images, videos & PDFs from reusable templates