Green mats - not good. Green mats no longer green, but splotched with paint, glue, blood, coffee - good!
To use green mat, wait until your desk/kitchen table/dining table/knees are beyond repair due to knife cuts and abrasions, then remember green mat stored by side of above work surface. Recover green mat from its 5 year-old hiding place, position over said damage, and use as required.
In case of failure of green mat, back-track to days before green mats, and spread out newspaper/brown paper/card, or wife's/girl friend's latest edition of 'Vogue' or similar publication, unless separated/divorced, then use alternative.
If not separated/divorced, utilise the above mentioned publication in order to gain experience of separation/divorce.