Tyvek paper will tolerate full immersion in water for several years without breakdown. White, non-toxic, chemically inert and recyclable. It is manufactured from finely spun polyethylene fibres which are then compressed to form the paper. A4 size, available in standard 55gm or heavy 75 gm.SeaWriter pencils are not suitable for writing on Tyvek.hite, non-toxic, chemically inert and recyclable. It is manufactured from finely spun polyethylene fibres which are then compressed to form the paper. A4 size, available in standard 55gm or heavy 75 gm. SeaWriter pencils are not suitable for writing on Tyvek.
The Medieval Ages, or the Middle Ages, is divided into three main parts as Early Middle Ages, High Middle Ages, and Late Middle Ages. Dark Ages is the Early Middle Ages, which is fixed roughly to be from 400 AD to 1000 AD by historians. The term, Dark Ages, was first coined by the Italian scholar Francesco Petrarca who was otherwise called Petrarch. It is interesting to note that there was religious struggle during the period of Dark Ages.
1 European Early Middle Ages. 2  Migration Period of c. 400 to 800 AD. 3  Saeculum obscurum or dark age in the history of the papacy, running from 904 to 964 AD.  Note: For a discussion on the usage of the phrase The Dark Ages for the above periods, see Dark Ages (historiography).