Is it me or are our Blobs & FABs getting way smaller?
I think that we are these days, and there are number of reasons for that. The main one being ( in my eyes ) angling pressure, something our waters see a lot of now, in fact post Covid I’ve never seen them so busy. And when it comes to pressured trout, then they are far more likely to take a smaller, less obtrusive Blob or FAB ( I think that may be a contradiction in terms, Thoughts?) on our heavily pressured waters. I think that’s also why we’ve seen a rise in the use of more muted colours on these fly styles flies. Washed out colours, Biscuit, Olive & Candy, that don’t scare the trout seem to be finding more favour. These less in your face flies really come into their own especially fished through the summer months and on into Autumn.

In the case of FABS the smaller fly, uses less foam and so is less buoyant allowing the user to present their fly through more of the water column, a free-fall technique that works very well with the now ubiquitous washing line technique. The old ones were constructed with a lot of foam, and they sat up high, like Boobies, but with less foam they can allow your cast of flies to crawl down through the water.

Large Blobs and FABS are ‘pulling’ flies and they are designed to get the trout to chase, and so they need bulk. The smaller ones we utilise are fishing more slowly, and covering more water too. Combine smaller Blobs and FABS with Nymphs and you have the ideal searching method up near the surface of the water.
For me, I arm myself with these flies in various sizes and colours, as I tie each to do a particular job, so it’s best that you’re prepared for all eventualities!

Caveat..
The oldies but goldies are still employed at times of coloured water, cold water and of course when the fish have been recently stocked.
The bigger, bulkier versions of this style of pattern definitely reign supreme early on in the reservoir year.

If you’d like to tie a particularly effective Blob that works very well in ALL sizes try this one…https://youtu.be/lmxiAu8bqdI