I love my front-loading washing machine. But I hate measuring out detergent.

The measuring cap that comes with my favourite detergent has lines that are almost impossible to see, especially when peering down into the cap in a moderately-lit laundry room.

But measuring carefully is vital, because the recommended amount is half a cap full, or less. Moreover, the shape chosen for the cap is one that encourages excessive use of laundry detergent. Studies of alcohol consumption have found that even experienced bartenders pour more into short wide glasses than tall slender ones – and most detergent measures are short and wide.

The consequence: most people use far too much detergent.

In a recent post on Worthwhile Canadian Initiative, I talked about economic reasons why manufacturers might want to encourage detergent use. When people use up detergent quickly, they buy detergent more often. That’s profitable provided that, when consumers come back, they buy the same brand again. In Canada, because there are so few detergent manufacturers, the odds of consumers sticking with the same brand are good.

Alternatively, hard to use measuring devices might be a form of price discrimination – people who read the instructions carefully and use the recommended amount pay less for detergent than those who fill the entire cap. Or perhaps it’s just a case of the folks in the bottle design department not talking to the product engineers.

But whatever the reason, it’s a golden opportunity for a homemade Christmas present. Just follow these simple instructions.

• Get the lid or scoop from your favourite brand of laundry detergent.

• Fill to the recommended level with water.

• Pour the water into a measuring cup to find out how much detergent you need. For my brand, the recommended amount for a large load is exactly ¼ cup of detergent.

• Go to the dollar store and buy an appropriate sized measure – in my example, a ¼ cup scoop.

• Write “large load” on the scoop with a Sharpie pen, and decorate artistically.

There you have it – the perfect gift for everyone on your shopping list, from a fledgling leaving the nest and doing laundry for the first time, to a loved one who can’t read the inside of a laundry cap without 200 watts of light. Or just a present to your future self.