Think of the work to get that intricate internal netting effect, then the coloured streaks, which do seem rarer as most Harrtil I see is clear glass
The fibres in Harrtil are woven glass -fibre, rather than individually created works. Heat, pulling, teasing apart of individual pieces of glass, gives a multitude of possibilities, which the five designers I told you about, envisaged, as a source of massive potential for innovative design. I recently saw, (last couple of days) a piece described as Harrtil, which was not, too regimented, none of the fibre patterns I recognise as Czech, and therefore merletto....
no additional colours...
Be aware though, that not all Czech Harrtil has a flint background. I have a stunning large exemplar, in an orange/rose. I suspect Smrckova for Chribska, but despite repeated enquiries in three languages, over two years, never once have I had a response, or confirmation.
Lovely items, a joy to visualise how they were made, and whatever, they will be worth, should be collected for beauty's sake rather than value.