
I think of the Painted Lady butterfly as "big and brown" but the predominent colour of the upperside of the wings is best described as orange/tan/pink. There are white markings against the dark brown/black edge of the wingtips. The underside of the wings are lighter-coloured than other common butterflies from the Nymphalidae family - mainly white and orange/tan/pink.
months seen in my garden: June, end July-October, most in August
garden plants that attract this species: 
      Buddleia, Ceratostigma, 
      Escallonia, Hebe, 
      Helichrysum, Heliotrope, 
      Hemp Agrimony, Hyssop, 
      Marigold, Red 
      Valerian, Scabious, 
      Sedum, Sweet William, 
      Verbena, Zinnia
First sighting of Painted Lady, 1 August 
      Painted Lady on Hebe, 5 August 
      
      Painted Lady on Verbena bonariensis at Berkeley Castle, 3 September 
      Painted Lady on Hemp agrimony at Coaley Peak, 3 September 
Painted Lady on Escallonia, 12 June
I have 90 digital images saved from 2003. Here's a selection of 10 (click on the thumbnail to view the full size image):
 
      On Buddleia Nanho Blue. August 
      2.
 
      On pink Hyssop. Side view. August 
      6.
 
      On Buddleia. Side view. August 
      4.
 
      Looking at the top of the wings from rear. Buddleia 'White Profusion' with 
      edge of Comma wing in foreground. August 
      4.
 
      Hanging upside down on Buddleia Nanho Blue. July 
      30.
 
      Top view on Sedum spectabile. August 
      23.
 
      From the back! July 30.
 
      Side view on Verbena. August 
      5.
 
      Another side view. August 12. 
      Picture taken in the "cut flower garden" at Stourhead, Wilts. 
      I think the plant is Zinnia. 
 
      I had read that Hemp Agrimony was a butterfly-attracting plant. Here's the 
      blurry evidence; Small Tortoiseshell in the foreground. August 
      12.
13 September 2002 on Scabious
      9 September 2000 on Ceratostigma
      15 August 2000 on Helichrysum
      14 August 1999 on Buddleia
      August 1998 on Hebe
If you'd like to try photographing butterflies, I recommend the Painted Lady butterfly as possibly the easiest to photograph.
Painted Lady butterflies like Buddleia and Verbena bonariensis in particular.
2003 was a good year for migrating Painted Lady butterflies and I recorded 8 sightings in June; in contrast, I didn't see a Painted Lady butterfly until August in 2002.
Size: 65mm (between Small White & Large White - see list of butterflies by size)
First Generation flight period: May-June
      Second Generation flight period: August-September
This butterfly species is classed as a regular migrant. They come from North Africa - sometimes in great clouds apparently. Once here they produce the next generation but can not survive the cold of a traditional British winter (except for the odd one in Cornwall?)
 Habitat:
      Larval Food Plants: Thistles, Burdocks, Mallows & Nettles
      Wild Nectar Plants: Hemp Agrimony
Family Group: Nymphalidae - see list of butterflies by family