Should I buy these cheap UK growth shares for my ISA?

These two UK growth shares appear to be exceptionally cheap right now. Should I invest in them in my Stocks and Shares ISA?

Printer in peril?

City analysts think De La Rue’s (LSE: DLAR) annual earnings will rebound more than 300% in the financial year to March 2022. This leaves the business trading on a low forward price-to-earnings (P/E) ratio of 12 times. It’s plenty cheap on paper, then. But I’m still not tempted to invest my hard-earned cash in this UK share.

The company’s share price has risen 13% during the past year but I expect the money printer to resume its downtrend again soon as the use of physical cash steadily declines. This UK share has lost around 60% of its value during the past five years.

Fresh consumer payments data from UK Finance illustrate De La Rue’s problems perfectly. This shows that the number of contactless payments on these shores rose 12% in 2020 to 9.6bn. Obviously contamination fears following the Covid-19 outbreak caused people to stop handling metal and paper money. But the switch to cards and contactless was rising strongly even before the pandemic. Contactless now accounts for 27% of all transactions versus just 7% four years ago.

Efforts to develop its authentication business could reap large rewards in its own right in the years ahead. But I fear this won’t be enough to offset the steady erosion of the UK small-cap share’s money manufacturing arm and especially in the post-coronavirus era. Remember that woes concerning its banknote printing business prompted De La Rue to warn that it could struggle to remain in business less than two years ago.

A better UK share to buy

I’d much rather buy 4Imprint Group (LSE: FOUR) shares for my Stocks and Shares ISA. City analysts think annual earnings here will boom 288% in 2021, leaving the UK share trading on a forward price-to-earnings growth (PEG) multiple of 0.2.

4Imprint’s share price has rose a less-impressive 6% during the past 12 months. But I think the company — which makes products that companies emblazon their logos over (think mugs, T-shirts and pencils) — is in much better shape than De La Rue to continue rising. Latest financials in May showed that “momentum in the business has built substantially” following coronavirus-hit 2020.

4Imprint’s strong performance is perhaps no surprise. History shows us that companies tend to supercharge the amount they spend on marketing activities as soon as economic conditions improve. But this isn’t the only reason why this particular UK share is thriving. It’s also grabbing market share in a highly-fragmented sector at an encouraging rate.

It’s true that earnings at 4Imprint could disappoint on the back of rocketing inflation. This is because the Federal Reserve could be forced to step in and raise rates, hitting the economic rebound in the UK share’s core US marketplace. Still, at current prices, I still think the product maker could be too cheap to miss and I’d happily buy it for my shares portfolio.