Experimenting as a self-employed person?

Dear all,

As an illustrator, I print and sell my work on postcards and posters. However, I also want to experiment with making linocuts so that I can sell them later, of course. Can I include training and materials in my accounts? I suspect so, because it’s for business purposes? But I also assume that there will be a lot of failed designs in the beginning during the learning process. Could the tax inspectorate then comment that you have to make certain material purchases twice?

Thanks in advance.

Kind regards,

Kim D.G.