This project is about creating an ergonoic and configurable chess set, that can be adapted to your site/app theme.
You can test youself on the configuration page which allows you to download SVG files with embedded customization. You can customize gradient colors, stroke color/widths, shadow on/off + blur size + offset etc. The square colors in the configuration page are not part of the piece theme but just for testing, so you can test how the customized SVGs look like on your board colors.
Can see a few configuration examples below in the "Examples" section
I'm providing three "serious" themes:
There are some alternative pieces in the "alternatives" subfolder. The SVGs are not to be uses as is but to be configured in the config page, the bright colors are just to highlight the gradient.
Additionally I have some fancy themes in the "fancy" subfolder. These are not configurable and just made available as is:
I am licensing these artworks with the MIT license.
In short, you can do what you want with this chess set, including possibly using it in your free or paid site program or app, as long as the author is cited in a way that is appropriate for the application.
I will appreciate if you send me an email (first.last AT gmail.com, with first=maurizio, last=monge), as I enjoy knowing that you are putting my chess pieces to good use for something. Not strictly required, I will just be happy if you do! I might also (very occasionally) update you if there is some major improvement in my my chess art project.