Kaley Cuoco compiled thousands of Polaroids as a wrap gift for her 'The Big Bang Theory' castmates.

The 33-year-old actress starred as Penny in the CBS sitcom - which ran from 2007 until May this year - and has said she spent all summer transferring around 2,000 images, which she had taken throughout the 12 years she'd worked on the show, onto hard drives for each of the cast and crew as a belated wrap gift.

She said: ''For 12 years on Big Bang I must have taken about 2,000 Polaroids of the cast ... so when we wrapped my sister and I ... put all the Polaroids onto a hard drive and sent it to the cast and crew.''

The gift took so long to prepare that her pals only just received their photos ''a few weeks ago'', but Kaley says they're excited to be able to look back at their time on the series.

She added: ''They just got it a few weeks ago, so they started texting me, like, 'I got the pictures!'''

And although the show aired its final episode in May, Kaley - who is married to Karl Cook - says she often watches reruns on television, where she barely even recognises her younger self.

Speaking to Kelly Clarkson on the singer's eponymous talk show, she said: ''It is on a lot and so I'll be flipping channels and once in a while I will turn it on, and if it's an older episode ... I don't even look like myself and I feel like I don't even sound like myself ... I went through a lot of changes - a lot of hair, a lot of different clothes.''