We took the plunge and made a notional purchase of shares in Greenock's British Polythene Industries on Wednesday morning after another highly-successful week for the majority of our share tips.

We had been monitoring them for some time and decided we couldn't afford to wait any longer as the price finally recovered to levels last seen in the autumn.

Trading conditions remain tough for the company, a big supplier to the farming and retail sectors, but figures due in March should benefit from increased efficiency and a better balance sheet, while BPI will be among the first to gain from any improvement in troubled euroland.

We have set our usual stop/loss figure of 10% below the notional purchase price, at which we will sell on any sustained price reversal.

Our existing tips continued to forge ahead on the back of the stronger stock market and the value of the four portfolios passed the £35,000 mark for the first time this year on Wednesday, up £1139 since January 2.

The latest 2013 selections were again to the fore with Scottish cloud computing hopeful Iomart up nearly 10% over the week and Diageo reversing previous losses despite some lukewarm comments from major stockbrokers.

But the biggest overall rise was shown by the 2010 list. Its total value jumped 3.6% after a fresh surge of support for Carr's Milling Industries and further gains by Scottish companies AG Barr, Aberdeen Asset Management and Devro.

The 2012 portfolio also gained from the Carr's and AAM performances to put on a further 2.2%.

The one disappointment was the 2011 portfolio with a fractional fall over the week as investors shunned safety-first SSE, Compass, Standard Life and Tesco in favour of more adventurous choices.

Hopefully, the addition of BPI to the list will help redress the balance.