While browsing the forums I frequently stumble on the argument "it's just clothes", generally coming from CDers making a point that CDing is a very normal thing to do, occasionally from GGs as well when they describe the activity of their CD significant other.
So, just clothes, right?
Let's say, panties, bra. Just clothes.
A pair of tights, a dress, shoes. Just clothes.
Rings, bracelets, necklace, earrings, a watch. Just clothes. Okay.
Done?
Well, for many crossdressers, the list extends a bit more.
Boobs. Just clothes?
Hip and buttocks forms, a garter. Just clothes?
Makeup, painted nails, wig. Just clothes?

It seems to me that when the list reached boobs, we slipped from dressing to transformation. Of course everyone may draw that fine line at a different level. In my personal case, as soon as I wear a pair of tights, or for that purpose any piece of female attire, it's not just clothes anymore, I'm starting an emotional journey that extends much beyond "just clothes".
Like a GG once said in a post: "Putting on women's clothing does not a girl make". Granted, however putting on boobs (or showing off your natural ones for the same illusion) seems a step farther than just a man wearing feminine apparel to his taste, and although it may not necessarily question your gender identity, it hints that your interest as a CDer goes slightly beyond the fabrics 🤔.
The argument "it's just clothes" for CDers going the full nine yards with forms, wig and makeup reminds me of its "it's for the comfort" sibling related to wearing panties rather male briefs, as it is a scientific fact that us males have such tender and delicate skin that cotton is poison ivy to us 😊.

Where do you draw the line yourself? When are clothes not just clothes anymore?