Found at Mill of Watten, Caithness by IS This could be a seed pan for germination seedlings in or a malting tile – these were perforated tile on the malting house floor which allowed air to flow up through the malt – see link It is possible that this is for germinating seeds as per this advert…
Found at Guardbridge, St Andrews
These broken malt tiles are both glazed and unglazed.
There is a broken mark which reads…. ” ? Ltd Nuneaton”
I believe the maker is Stanley Bros Ltd, Nuneaton.
Source below – Malt kilns in Gloucestershire by Amber Patrick –
Below – the examples found at Guardbridge – see pattern 1 above.