In addition to mining chemical information from printed literature, information can also be found in hand-written laboratory notebooks that were never before attempted to be digitised and mined for chemical structure information. In these notebooks, chemical structures are typically manually drawn, which means there is an even higher degree of diversity in the way molecular structures are depicted. Unless the chemists choose to publish their novel findings together with related information in a publication, these hand-drawn structures are never converted into machine-readable formats. Recognising and interpreting hand-drawn chemical structures is challenging due to the variety of drawing styles and the complexity of each individual's handwriting . It is, therefore crucial to develop accurate tools for recognising hand-drawn chemical structures to digitise them. Digitising hand-written chemical structures enables high-quality data-driven research and preserves information for future use.