Hi Francesca,
I must admit I have not used the .10 thick lashes for the past year.
They are too much work with little result !
All my full-sets consist of using the .20's to set my frame and then I'll combine the
.15's to fill in the spaces. This gives a beautiful natural look.
If the client wants a dramatic WOW effect, then I'll use the .20's
thoughout - providing they don't have fluffy fine natural lashes!
Also the thickness of the .15 will always outlast the .20's or .25's.
Don't stress about it - It's all normal ;D
Very rarely do I use the .25 thick lashes, because it's a VERY rare client that can wear them.
Firstly, the thicker the lash - the heavier the weight.
Secondly, the thicker the extension - the less flexability it has.
Also this type of lash need's more glue to secure the bond.
More glue need's more drying time between lashes, which can slow you down a bit.
Even with the Flash Lash glue
The natural lash needs to be quite thick/strong in order to support the weight of the .25's lashes. I do NOT recommend that a full-set be done exclusively. When the odd occasion arises, I'll use the .25's only to set my frames/structure in the outer 3/4 of each eye and then fill-in between with the .20's and a few .15's in the inner 1/4. But I will not go past a 10mm or 11mm length.
I do have a couple of questions about your application:
1. Do you bond the extension to the TOP, UNDER or SIDE of the natural lash?
2. When you say the lashes Irritate the clients, what exactly is irritating them?
Eg. Is it the weight?, Are they poking the clients eyes at the base? Is it the flexability?
3. When your using the .25's are you using enough glue?
4. Which glue are you using?
5. When the client returns, are her natural lashes in tact? (or are they broken or fallen out?)