The recent talk about mechanical pencils has me breaking out a couple of pencils from the "vault". Have been on a pen kick with the quest for finding the perfect refill, and have not used any of my pencils for quite some time. Due to the stockpile of leads I have accumulated I have not bought any new lead in at least 15 years. Now somethings are amazingly static, but in many technology and manufacturing processes continue to improve/evolve. Hence the question: What is the current gold standard in mechanical pencil lead? I use 0.3mm almost exclusively, so the key characteristic is strength/flexibility to cut down on lead breakage. Typically use F or H as I find that HB and softer are consumed too quickly, and break more easily.