The Tengwar alphabet is well suited to writing Welsh, possibly because Tolkien based Sindarin, one of the languages he invented, partly on Welsh. The version below is similar to the Sindarin mode and was devised by Simon Ager, the author of this site.
Genir pawb yn rhydd ac yn gydradd â'i gilydd mewn urddas a hawliau. Fe'u cynysgaeddir â rheswm a chydwybod, a dylai pawb ymddwyn y naill at y llall mewn ysbryd cymodlon.
All human beings are born free and equal in dignity and rights. They
are endowed with reason and conscience and should act towards one another
in a spirit of brotherhood.
(Article 1 of the Universal Declaration of Human Rights)
This is a Tengwar mode for Welsh devised by Jehudá Ronén and based on the Sindarin mode of mode of Beleriand.
Tengwar for Quenya, Tengwar for Sindarin, Tengwar for English, Tengwar for High Valyrian, Tengwar for Hungarian, Tengwar for Icelandic, Tengwar for Portugese, Tengwar for Scottish Gaelic (1), Tengwar for Scottish Gaelic (2), Tengwar for Spanish, Tengwar for Latin American Spanish, Tengwar for Welsh
Another Tengwar mode for Welsh devised by Jehudá Ronén and based on the Sindarin mode of Beleriand: http://digitalwords.net/259/