Yes, the ink in these markers is alcohol-based. This product is specifically described as a "Zestaw Markerów Alkoholowych", which means a set of alcohol-based markers.

Each pen has a thick and a thin tip. So they are not different variants, but each pen can do both.

The pens in the Extralink alcohol marker set (262 pieces, manufacturer's no. MARKERY 262SZT) have a wide and a thin side. Each brand is therefore double-sided: one side has a thick tip for broad strokes and the other side has a fine tip for detailed work.

Yes, the pens in the Extralink Alcohol Marker Set (262 pieces, manufacturer's no. MARKERY 262SZT) actually have a wide and a thin side. Each brand is double-sided: one side has a thick tip for broad strokes and the other side has a fine tip for detailed work.