What can I do with yellowing decals?

Yellowing of waterslide decal sheets is periodically a problem for modellers, especially those who enjoy collecting vintage kits. Simply put, the carrier film backing of decals ages over time and can produce a noticeable yellowing of the decals. This can be awkward as it can seriously detract from the enjoyment of the build and the eventual look of the completed model. Thankfully, there are a number of options available to modellers to help alleviate this situation.

Cut away the yellowing: In some cases, it may be possible to cut away significant areas of yellowing carrier film with a sharp hobby knife and a cutting mat. This can be especially effective in the case of national insignia where the yellowed backing film is less of a problem. Lettering can be a trickier prospect as the transparent backing will provide rigidity and structure in the case of certain letters such as S and G.

Replacement Decals: It may be possible to replace the yellowed decals with replacement versions. Although the kit may not be in a current production run with the original manufacturers, many after-market providers produce a wide range of specialist decals for popular subjects. These will inevitably have the benefit of being newer and having been produced by more modern printing processes. It may also be possible to search for replacements of the original decals through modelling forums or via eBay, although original, they may not have suffered yellowing which still makes this a viable option.

Sun Bleach: Another option that is popular in these circumstances and can be remarkably effective is to sun-bleach the decals. Tape the decal backing sheet onto the inside of a window in direct sunlight. The sunlight can be very effective at bleaching away the yellowing on the decal's carrier film. It is important to check the decals on a regular basis as excess sunlight can also bleach away the colouring on the decals themselves. With care, this could also be used as an intentional process by a modeller who is happy to trade off a little bit of colour loss as it will lead to a fading on the decals. This can be useful if the modeller wishes to produce a highly weathered or distressed look on their model, as the fading of the decals will then be in keeping with the desired 'look' for the model.