The padded envelopes arrive once a month. They contain just a few items of stationery, a book and materials for a maths activity.
But the foster children who receive these packages find them almost as exciting as Christmas presents. Rose Griffiths, a Leicester university researcher monitoring the effect of the Letterbox Club, a support programme for foster families, said that the parcels appeared to have had the desired effects.
"They seem to have increased the frequency of foster carers reading to children, and of children asking to be read to," she told the Bera conference.
"There is also evidence of children reading to each other and talking about how to improve their reading."
The programme has been piloted in two unnamed local education authorities over the past two years, with 57 children aged seven to 11. The impact on their educational progress has yet to be properly evaluated but initial signs are positive. The reading ages of several children increased substantially in the first year, and most had a more positive attitude towards schoolwork.
However, the parcels were appreciated for more than their contents.
"Several children said it was the first time they had ever had a letter or a parcel," Ms Griffiths said.
"Many children had kept the envelopes. In the third parcel, children were each given two sheets of personalised name labels saying 'This book belongs to ...' with their name filled in.
"Three foster carers said their children bought second-hand books at the next car boot sale or jumble sale they went to so they could put their labels in them."