'Can Graphic Design be considered Art?' It's one of those questions that comes up time and again, and one of those questions to which the quick glib answer is as good as any 10,000 word thesis response: 'Yeah, sure, if you want it to be'.

But the intersection between design and art can be an interesting place to hang out, and we were reminded of this over the weekend, when we checked out the new Ed Ruscha and Sophie Calle shows that opened in town recently. Both artists create work that plays with text extensively, though in very distinct ways.

The retrospective of American artist Ed Ruscha (pronounced Rew-shay fact-fans) is at the Hayward. Ruscha actually studied as a graphic designer at Chouinard Art Institute (now California Institute of the Arts), and his first job was as a layout artist at an advertising agency.

His career has spanned fifty years, and has constantly shown a preoccupation with typography and lettering, often in an almost abstract sense, using words for their forms rather than their meaning; although in the 80s his work started to use longer sentences, set in his own typeface, Boy Scout Utility Modern (which looks like a buggered-up version of Wim Crouwel's Gridnik).

The show features work from right across Ruscha's career but, apart from the first room, it left us feeling a little flat...

In contrast, Sophie Calle's show Talking to Strangers, at the Whitechapel Gallery, left us feeling excited and energised. We've loved her work since seeing her fantastic show Double Game at Camden Arts Centre back in 1999 - check out the disgustingly gorgeous book of the same name that Vince Frost designed for her - you'll find it on his site under Discipline > Book Design. (And heck, you can still pick up used copies of Double Game
on Amazon.)

The main installation at the Whitechapel show is Take Care of Yourself, first shown at the 2007 Venice Biennale. The work is based on a break-up email sent to her by an ex-lover. Calle sent the email on to 107 women (including judges, lawyers, ballerinas, actresses, her mum...) and asked them to interpret it. She then documented the results in utterly beautiful pieces that combine photographs of the women and typographic representations of their repsonses (as well as in a few short film pieces). Suitably for a work based on written communication, the installation feels a bit like walking through a book. It's really great, and well worth a visit.

The Ruscha show runs until 10 January, the Calle until 3 January. Read more about Sophie Calle in this Guardian interview, or pick up a copy of Sophie Calle: M'as tu vue? - Did you see me?.