Regulating the Aftertouch is definitely a touchy-feely operation!

Once keyboard and keys, brushing-up rollers, levers-to-hammers, blow distance, jacks-to-rollers, set-off & drop have all been adjusted, basic depth of touch and aftertouch can be regulated.

The depth of touch is just a basic setting. The touch depth block is just a guide. The actual and ultimate setting is determined by the FEEL of the jack releasing from the roller (the hammer releasing from the key): this is the AFTERTOUCH. Super-thin paper washers (factors of 0.01 mm) make all the difference to evenness (regulation) of this setting from key to key.