I was surprised to find EGGM Enterprises has a 6″x6″ Solderite Soldering Pad for $6.75. The ad proclaims one of the features is it’s a non-asbestos pad — you know, like you could buy an asbestos pad anymore.
It is extremely heat-resistant and work can be placed directly on the pad for (hard, silver) soldering. The white surface reflects the heat as well. It is relatively soft and can be shaped to hold workpieces for production soldering. It’s pretty handy, if only to protect your benchtop.
6″x6″ Solderite Soldering Pad [EGGM Enterprises]