Dear Hans, a few comments:
- Do you need to represent all four substituents around the stereogenic center? Because so often, hydrogen if bound to carbon is implicit in the formulae, without ambiguity. And if all four substitutents around the carbon need to be shown -- as to introduce / train / test usage of CIP rules -- two substituents and the (implicit) carbon in one layer, one substituent above, the fourth below the drawing plane could simplify the drawing. Except when up to _explain_ Fischer formulae for carbohydrates. - Re tapered bonds/dashed bonds. Do you refer to _dashed bonds_ on one, and a _bold but non-tapered bond_ on an other stereogenic center of the same molecule? If so, this describes the two substitutents only in _trans_ relationship to each other, because of lack for further evidence about their absolute configuration. Or to describe a mixture of diastereomers, which could be for instance a 1:3 ratio of (R,R)- and (S,S)-tartaric acid, or a 1:1 racemate -- vague. _Dashed_ sometimes is misused instead of _hashed_ (and opposite to the bold wedge). However _dashed_ (and even more so, _dotted_ lines) typically symbolize bonds weaker than a typical covalent single bond, between hydrogen bond donors and acceptors. It is up to you if you use a molecule editor with subsequent export of an image (an old open access review: https://www.gunda.hu/dprogs/), or construct the structures. The later approach is a bit of a niche (as seen for instance around chemfig for LaTeX e.g., https://doi.org/10.1186/1758-2946-4-24) and less quick to change and adjust _manually_ if needed (cf. Table I in Brecher's compilation of guidelines, https://doi.org/10.1351/pac200880020277). Kind regards, Norwid
