The Blob!
THE BLOB! is an expression I took from a low budget Science fiction/horror type movie where a huge BLOB of goo or whatever it was threatened the world.
THE BLOB! in flytying is the red “butt” of some flies you can see here. I saw this in an article in a German flyfishing magazine. There were some flies with a small red dot on the “butt” tied by a Swedish grayling expert. He did this with all his flies, so I guessed it must be worth the effort. I also remembered some of the most famous grayling/trout patterns here e.g. the Red Tag or the “Orscherl” of Hans Gebethsroither. They all had the same feature: a red or orange “butt”. And as I have had good success with other orange/attractor coloured patterns I wanted to include this into some of my flies.
So I searched for a material that would look nice and stand a few fish. I found Window colours which comes in every colour imaginable and was more durable and easier than textile colour to apply. Of course this is a pre-tying procedure as the colour has to dry for 15 minutes, but sometimes I do it because it is nice and adds a bit of attraction to some flies.
THE BLOB! is more durable if you make it over a few turns of thread. It might not look as nice as here but holds longer.
Of course you could use orange or pink tying thread instead but if you want to take the trouble give THE BLOB of Window colours a try.