Semi-dry jointing mortar - Jointing of indian stone flags

[Eeyore]

I have read much of this excellent web site and picked up a lot of very usefull info that should make my forthcoming DIY patio project a much more straight forward undertaking (so thank you Tony).

I am using Indian Sandstone flags and plan to use a coloured semi-dry mortar for jointing as per the case study on this site. In mixing the semi-dry mortar should I use a plasticiser in the mix? And if so, is a liquid or dry plasticiser best in a semi-dry mix?

[Tony McC]

You shouldn't need a plasticiser. Firstly; using semi-dry a plasticiser wouldn't really work ads they are intended for wet mortars, and secondly, many dyes and pigments already incorporate a plasticising agent in powder form.